OT funny thing
I have a car Fiesta 1.3 Endura 2001 2002.
It is fitted with a Ford CD car radio. Up until two days ago the car radio worked fine (and it still does ). Here's the problem; about 18 months ago the rear screen heater stopped working. I looked at it and couldn't see anything obvious. I checked the connectors and the switch and the fuses. put to one side to do when I could fit it in. On Saturday I got the workshop manual out and the multimeter. 10 minutes late I locate the problem, the relay which is mounted up behind the fuse box appears to not work. Upon examination of the relay the high current terminal has overheated and gone open circuit. Cleaned up and swapped that relay for another one of the same type mounted in the same fuse box checked circuits and it's okay. Later that day I go to Tesco's and radio isn't working very well, low signal. I think to myself that's funny! Just out of interest I turn off the rear screen heater. The radio now works. So I turn the heat back on again, and the radio goes hissy, turn it off and the radio is fine. I've rechecked that the rear screen circuits are all intact and not arcing or anything but it got me beat (that's not hard). Any ideas ? |
OT funny thing
On Tuesday, December 11, 2012 1:16:58 PM UTC, Gary wrote:
I have a car Fiesta 1.3 Endura 2001 2002. It is fitted with a Ford CD car radio. Up until two days ago the car radio worked fine (and it still does ). Here's the problem; about 18 months ago the rear screen heater stopped working. I looked at it and couldn't see anything obvious. I checked the connectors and the switch and the fuses. put to one side to do when I could fit it in. On Saturday I got the workshop manual out and the multimeter. 10 minutes late I locate the problem, the relay which is mounted up behind the fuse box appears to not work. Upon examination of the relay the high current terminal has overheated and gone open circuit. Cleaned up and swapped that relay for another one of the same type mounted in the same fuse box checked circuits and it's okay. Later that day I go to Tesco's and radio isn't working very well, low signal. I think to myself that's funny! Just out of interest I turn off the rear screen heater. The radio now works. So I turn the heat back on again, and the radio goes hissy, turn it off and the radio is fine. I've rechecked that the rear screen circuits are all intact and not arcing or anything but it got me beat (that's not hard). Any ideas ? The drain on the battery from the working heater is causing the radio problems, maybe the car battery is on it's way out, have you tried measuring the voltage when the heaters on. Clucthcing at straws perhaps I'd blame the cold weather ;-) |
OT funny thing
On 11/12/2012 13:24, whisky-dave wrote:
On Tuesday, December 11, 2012 1:16:58 PM UTC, Gary wrote: I have a car Fiesta 1.3 Endura 2001 2002. It is fitted with a Ford CD car radio. Up until two days ago the car radio worked fine (and it still does ). Here's the problem; about 18 months ago the rear screen heater stopped working. I looked at it and couldn't see anything obvious. I checked the connectors and the switch and the fuses. put to one side to do when I could fit it in. On Saturday I got the workshop manual out and the multimeter. 10 minutes late I locate the problem, the relay which is mounted up behind the fuse box appears to not work. Upon examination of the relay the high current terminal has overheated and gone open circuit. Cleaned up and swapped that relay for another one of the same type mounted in the same fuse box checked circuits and it's okay. Later that day I go to Tesco's and radio isn't working very well, low signal. I think to myself that's funny! Just out of interest I turn off the rear screen heater. The radio now works. So I turn the heat back on again, and the radio goes hissy, turn it off and the radio is fine. I've rechecked that the rear screen circuits are all intact and not arcing or anything but it got me beat (that's not hard). Any ideas ? The drain on the battery from the working heater is causing the radio problems, maybe the car battery is on it's way out, have you tried measuring the voltage when the heaters on. Clucthcing at straws perhaps I'd blame the cold weather ;-) full voltage. it is as if the aerial amp is being turned off. it is prosibly an earth problem but it is not obvious where to look. thanks |
OT funny thing
What was the other relay being used for that he nicked though, kind of makes
you wonder.... Some cars do use the screen heaters as an aerial. Ther eis usually though chokes in the circuit to stop problems with the apparent earthing of the other end of the heater! Brian Brian -- From the Sofa of Brian Gaff Reply address is active "whisky-dave" wrote in message ... On Tuesday, December 11, 2012 1:16:58 PM UTC, Gary wrote: I have a car Fiesta 1.3 Endura 2001 2002. It is fitted with a Ford CD car radio. Up until two days ago the car radio worked fine (and it still does ). Here's the problem; about 18 months ago the rear screen heater stopped working. I looked at it and couldn't see anything obvious. I checked the connectors and the switch and the fuses. put to one side to do when I could fit it in. On Saturday I got the workshop manual out and the multimeter. 10 minutes late I locate the problem, the relay which is mounted up behind the fuse box appears to not work. Upon examination of the relay the high current terminal has overheated and gone open circuit. Cleaned up and swapped that relay for another one of the same type mounted in the same fuse box checked circuits and it's okay. Later that day I go to Tesco's and radio isn't working very well, low signal. I think to myself that's funny! Just out of interest I turn off the rear screen heater. The radio now works. So I turn the heat back on again, and the radio goes hissy, turn it off and the radio is fine. I've rechecked that the rear screen circuits are all intact and not arcing or anything but it got me beat (that's not hard). Any ideas ? The drain on the battery from the working heater is causing the radio problems, maybe the car battery is on it's way out, have you tried measuring the voltage when the heaters on. Clucthcing at straws perhaps I'd blame the cold weather ;-) |
OT funny thing
Vehicles are indeed strange things..
-- From the Sofa of Brian Gaff Reply address is active "whisky-dave" wrote in message ... On Tuesday, December 11, 2012 1:16:58 PM UTC, Gary wrote: I have a car Fiesta 1.3 Endura 2001 2002. It is fitted with a Ford CD car radio. Up until two days ago the car radio worked fine (and it still does ). Here's the problem; about 18 months ago the rear screen heater stopped working. I looked at it and couldn't see anything obvious. I checked the connectors and the switch and the fuses. put to one side to do when I could fit it in. On Saturday I got the workshop manual out and the multimeter. 10 minutes late I locate the problem, the relay which is mounted up behind the fuse box appears to not work. Upon examination of the relay the high current terminal has overheated and gone open circuit. Cleaned up and swapped that relay for another one of the same type mounted in the same fuse box checked circuits and it's okay. Later that day I go to Tesco's and radio isn't working very well, low signal. I think to myself that's funny! Just out of interest I turn off the rear screen heater. The radio now works. So I turn the heat back on again, and the radio goes hissy, turn it off and the radio is fine. I've rechecked that the rear screen circuits are all intact and not arcing or anything but it got me beat (that's not hard). Any ideas ? The drain on the battery from the working heater is causing the radio problems, maybe the car battery is on it's way out, have you tried measuring the voltage when the heaters on. Clucthcing at straws perhaps I'd blame the cold weather ;-) |
OT funny thing
In article ,
Gary wrote: Later that day I go to Tesco's and radio isn't working very well, low signal. I think to myself that's funny! Just out of interest I turn off the rear screen heater. The radio now works. So I turn the heat back on again, and the radio goes hissy, turn it off and the radio is fine. I've rechecked that the rear screen circuits are all intact and not arcing or anything but it got me beat (that's not hard). Any ideas ? Does it use the rear screen element as an aerial? If so perhaps the amplifier/isolator unit is not being powered correctly after your repair. -- *I thought I wanted a career. Turns out I just wanted paychecks. Dave Plowman London SW To e-mail, change noise into sound. |
OT funny thing
On 11/12/2012 13:54, Dave Plowman (News) wrote:
In article , Gary wrote: Later that day I go to Tesco's and radio isn't working very well, low signal. I think to myself that's funny! Just out of interest I turn off the rear screen heater. The radio now works. So I turn the heat back on again, and the radio goes hissy, turn it off and the radio is fine. I've rechecked that the rear screen circuits are all intact and not arcing or anything but it got me beat (that's not hard). Any ideas ? Does it use the rear screen element as an aerial? If so perhaps the amplifier/isolator unit is not being powered correctly after your repair. Or perhaps the original relay damage was caused by failure of the choke that isolated the element's power supply from its aerial function, so now when powered, you are in effect grounding your aerial as well? -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
OT funny thing
On Tue, 11 Dec 2012 14:36:08 +0000, John Rumm wrote:
On 11/12/2012 13:54, Dave Plowman (News) wrote: In article , Gary wrote: Later that day I go to Tesco's and radio isn't working very well, low signal. I think to myself that's funny! Just out of interest I turn off the rear screen heater. The radio now works. So I turn the heat back on again, and the radio goes hissy, turn it off and the radio is fine. I've rechecked that the rear screen circuits are all intact and not arcing or anything but it got me beat (that's not hard). Any ideas ? Does it use the rear screen element as an aerial? If so perhaps the amplifier/isolator unit is not being powered correctly after your repair. Or perhaps the original relay damage was caused by failure of the choke that isolated the element's power supply from its aerial function, so now when powered, you are in effect grounding your aerial as well? A capacitor will also be needed to isolate any DC from the aerial input. -- Regards, Paul Herber, Sandrila Ltd. http://www.sandrila.co.uk/ twitter: @sandrilaLtd |
OT funny thing
"Brian Gaff" wrote... On Saturday I got the workshop manual out and the multimeter. 10 minutes late I locate the problem, the relay which is mounted up behind the fuse box appears to not work. Upon examination of the relay the high current terminal has overheated and gone open circuit. Cleaned up and swapped that relay for another one of the same type mounted in the same fuse box checked circuits and it's okay. Later that day I go to Tesco's and radio isn't working very well, low signal. I think to myself that's funny! Just out of interest I turn off the rear screen heater. The radio now works. So I turn the heat back on again, and the radio goes hissy, turn it off and the radio is fine. I've rechecked that the rear screen circuits are all intact and not arcing or anything but it got me beat (that's not hard). Any ideas ? The drain on the battery from the working heater is causing the radio problems, maybe the car battery is on it's way out, have you tried measuring the voltage when the heaters on. Clucthcing at straws perhaps I suspect it uses the rear heater element (tracks on the window, like my Honda had) as the aerial - and the original relay may have an inductor or similar on one or both of the "heat" terminals to prevent the radio signal being shorted by the car's electrical system - when the heater comes on one end of the element is effectively earthed, so you lose most of the signal. You may need to get an *exactly match* for the relay you took out, or you could look at adding an inductor in the lead from relay to element? Dave H, (the other one) |
OT funny thing
Gary formulated on Tuesday :
I have a car Fiesta 1.3 Endura 2001 2002. It is fitted with a Ford CD car radio. Up until two days ago the car radio worked fine (and it still does ). Here's the problem; about 18 months ago the rear screen heater stopped working. I looked at it and couldn't see anything obvious. I checked the connectors and the switch and the fuses. put to one side to do when I could fit it in. On Saturday I got the workshop manual out and the multimeter. 10 minutes late I locate the problem, the relay which is mounted up behind the fuse box appears to not work. Upon examination of the relay the high current terminal has overheated and gone open circuit. Cleaned up and swapped that relay for another one of the same type mounted in the same fuse box checked circuits and it's okay. Later that day I go to Tesco's and radio isn't working very well, low signal. I think to myself that's funny! Just out of interest I turn off the rear screen heater. The radio now works. So I turn the heat back on again, and the radio goes hissy, turn it off and the radio is fine. I've rechecked that the rear screen circuits are all intact and not arcing or anything but it got me beat (that's not hard). Any ideas ? Assuming as many do today - the rear screen heater is used as the antenna for the radio and the printed tracks on the glass are damaged, the poor tracks will generate masses of interference when the screen heater is turned on. -- Regards, Harry (M1BYT) (L) http://www.ukradioamateur.co.uk |
OT funny thing
On 11/12/2012 15:36, Harry Bloomfield wrote:
Gary formulated on Tuesday : snip I've rechecked that the rear screen circuits are all intact and not arcing or anything but it got me beat (that's not hard). Any ideas ? Assuming as many do today - the rear screen heater is used as the antenna for the radio and the printed tracks on the glass are damaged, the poor tracks will generate masses of interference when the screen heater is turned on. Why? We're talking 12V here, not a voltage that is going to jump some distance. Is there is a bad connection, then it would still show when the heater is turned off. |
OT funny thing
On 11/12/2012 14:44, Paul Herber wrote:
On Tue, 11 Dec 2012 14:36:08 +0000, John Rumm wrote: On 11/12/2012 13:54, Dave Plowman (News) wrote: In article , Gary wrote: Later that day I go to Tesco's and radio isn't working very well, low signal. I think to myself that's funny! Just out of interest I turn off the rear screen heater. The radio now works. So I turn the heat back on again, and the radio goes hissy, turn it off and the radio is fine. I've rechecked that the rear screen circuits are all intact and not arcing or anything but it got me beat (that's not hard). Any ideas ? Does it use the rear screen element as an aerial? If so perhaps the amplifier/isolator unit is not being powered correctly after your repair. Or perhaps the original relay damage was caused by failure of the choke that isolated the element's power supply from its aerial function, so now when powered, you are in effect grounding your aerial as well? A capacitor will also be needed to isolate any DC from the aerial input. Yup, although there is a fair chance the radio will have that internally. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
OT funny thing
In article ,
John Rumm wrote: Or perhaps the original relay damage was caused by failure of the choke that isolated the element's power supply from its aerial function, so now when powered, you are in effect grounding your aerial as well? A capacitor will also be needed to isolate any DC from the aerial input. Yup, although there is a fair chance the radio will have that internally. The installations I've seen that use the rear screen as an aerial have an amp mounted close to it - which I assume removes all the nasties before sending it off to the head unit. -- *If at first you don't succeed, then skydiving definitely isn't for you * Dave Plowman London SW To e-mail, change noise into sound. |
OT funny thing
On Dec 11, 3:36*pm, Harry Bloomfield
wrote: Gary formulated on Tuesday : Assuming as many do today - the rear screen heater is used as the antenna for the radio and the printed tracks on the glass are damaged, the poor tracks will generate masses of interference when the screen heater is turned on. We have that problem on an ancient Skoda which does have a separate radio aerial. Jonathan |
OT funny thing
On Tue, 11 Dec 2012 15:31:17 -0000, "news.virginmedia.com"
wrote: "Brian Gaff" wrote... On Saturday I got the workshop manual out and the multimeter. 10 minutes late I locate the problem, the relay which is mounted up behind the fuse box appears to not work. Upon examination of the relay the high current terminal has overheated and gone open circuit. Cleaned up and swapped that relay for another one of the same type mounted in the same fuse box checked circuits and it's okay. Later that day I go to Tesco's and radio isn't working very well, low signal. I think to myself that's funny! Just out of interest I turn off the rear screen heater. The radio now works. So I turn the heat back on again, and the radio goes hissy, turn it off and the radio is fine. I've rechecked that the rear screen circuits are all intact and not arcing or anything but it got me beat (that's not hard). Any ideas ? The drain on the battery from the working heater is causing the radio problems, maybe the car battery is on it's way out, have you tried measuring the voltage when the heaters on. Clucthcing at straws perhaps I suspect it uses the rear heater element (tracks on the window, like my Honda had) as the aerial - and the original relay may have an inductor or similar on one or both of the "heat" terminals to prevent the radio signal being shorted by the car's electrical system - when the heater comes on one end of the element is effectively earthed, so you lose most of the signal. You may need to get an *exactly match* for the relay you took out, or you could look at adding an inductor in the lead from relay to element? Dave H, (the other one) That's what I thought too. I presume there isn't a conventional aerial on this car so it's a good guess that the heated rear window is providing this function. If so, there will be a couple of RF chokes to isolate the screen at RF, the only problem is that I would expect these chokes to be near the screen, not under the dash or in the engine compartment. Incidentally I had a Civic with that arrangement for a while, I hated the car for various reasons, but the radio reception on AM and FM was superb. -- Graham. %Profound_observation% |
OT funny thing
Fredxx formulated the question :
On 11/12/2012 15:36, Harry Bloomfield wrote: Gary formulated on Tuesday : snip I've rechecked that the rear screen circuits are all intact and not arcing or anything but it got me beat (that's not hard). Any ideas ? Assuming as many do today - the rear screen heater is used as the antenna for the radio and the printed tracks on the glass are damaged, the poor tracks will generate masses of interference when the screen heater is turned on. Why? We're talking 12V here, not a voltage that is going to jump some distance. Is there is a bad connection, then it would still show when the heater is turned off. I can assure you I do not what I am talking about. -- Regards, Harry (M1BYT) (L) http://www.ukradioamateur.co.uk |
OT funny thing
In article
, Jonathan wrote: On Dec 11, 3:36 pm, Harry Bloomfield wrote: Gary formulated on Tuesday : Assuming as many do today - the rear screen heater is used as the antenna for the radio and the printed tracks on the glass are damaged, the poor tracks will generate masses of interference when the screen heater is turned on. We have that problem on an ancient Skoda which does have a separate radio aerial. when I think about it, I had that problem on my no-so-ancient Citrφen (only 10½ years). This had a separate roof aerial at the rear of the car. Replacing the aerial cured the problem. It had broken internally - probably because it got bent rather severely when I carried sheets of plywood on the roof bars. -- From KT24 Using a RISC OS computer running v5.18 |
OT funny thing
In article ,
Gary writes: I have a car Fiesta 1.3 Endura 2001 2002. It is fitted with a Ford CD car radio. Up until two days ago the car radio worked fine (and it still does ). Here's the problem; about 18 months ago the rear screen heater stopped working. I looked at it and couldn't see anything obvious. I checked the connectors and the switch and the fuses. put to one side to do when I could fit it in. On Saturday I got the workshop manual out and the multimeter. 10 minutes late I locate the problem, the relay which is mounted up behind the fuse box appears to not work. Upon examination of the relay the high current terminal has overheated and gone open circuit. Cleaned up and swapped that relay for another one of the same type mounted in the same fuse box checked circuits and it's okay. Later that day I go to Tesco's and radio isn't working very well, low signal. I think to myself that's funny! Just out of interest I turn off the rear screen heater. The radio now works. So I turn the heat back on again, and the radio goes hissy, turn it off and the radio is fine. I've rechecked that the rear screen circuits are all intact and not arcing or anything but it got me beat (that's not hard). A common problem with older Fiestas is that the earth return from the rear heater (and rear wiper if you have one) is via the boot lid hinges, and they go high impedance. Connecting an earthing strap between the boot lid and the car body fixes this. Don't know if it's related to your aerial problem though. -- Andrew Gabriel [email address is not usable -- followup in the newsgroup] |
OT funny thing
On 11/12/12 16:06, John Rumm wrote:
On 11/12/2012 14:44, Paul Herber wrote: On Tue, 11 Dec 2012 14:36:08 +0000, John Rumm wrote: On 11/12/2012 13:54, Dave Plowman (News) wrote: In article , Gary wrote: Later that day I go to Tesco's and radio isn't working very well, low signal. I think to myself that's funny! Just out of interest I turn off the rear screen heater. The radio now works. So I turn the heat back on again, and the radio goes hissy, turn it off and the radio is fine. I've rechecked that the rear screen circuits are all intact and not arcing or anything but it got me beat (that's not hard). Any ideas ? Does it use the rear screen element as an aerial? If so perhaps the amplifier/isolator unit is not being powered correctly after your repair. Or perhaps the original relay damage was caused by failure of the choke that isolated the element's power supply from its aerial function, so now when powered, you are in effect grounding your aerial as well? A capacitor will also be needed to isolate any DC from the aerial input. Yup, although there is a fair chance the radio will have that internally. standard input is either a coil to ground, which would smoke on DC, or a low value kerpuffitor, which will block it. -- Ineptocracy (in-ep-toc-ra-cy) a system of government where the least capable to lead are elected by the least capable of producing, and where the members of society least likely to sustain themselves or succeed, are rewarded with goods and services paid for by the confiscated wealth of a diminishing number of producers. |
OT funny thing
On 11/12/2012 17:04, Graham. wrote:
On Tue, 11 Dec 2012 15:31:17 -0000, "news.virginmedia.com" wrote: "Brian Gaff" wrote... On Saturday I got the workshop manual out and the multimeter. 10 minutes late I locate the problem, the relay which is mounted up behind the fuse box appears to not work. Upon examination of the relay the high current terminal has overheated and gone open circuit. Cleaned up and swapped that relay for another one of the same type mounted in the same fuse box checked circuits and it's okay. Later that day I go to Tesco's and radio isn't working very well, low signal. I think to myself that's funny! Just out of interest I turn off the rear screen heater. The radio now works. So I turn the heat back on again, and the radio goes hissy, turn it off and the radio is fine. I've rechecked that the rear screen circuits are all intact and not arcing or anything but it got me beat (that's not hard). Any ideas ? The drain on the battery from the working heater is causing the radio problems, maybe the car battery is on it's way out, have you tried measuring the voltage when the heaters on. Clucthcing at straws perhaps I suspect it uses the rear heater element (tracks on the window, like my Honda had) as the aerial - and the original relay may have an inductor or similar on one or both of the "heat" terminals to prevent the radio signal being shorted by the car's electrical system - when the heater comes on one end of the element is effectively earthed, so you lose most of the signal. You may need to get an *exactly match* for the relay you took out, or you could look at adding an inductor in the lead from relay to element? Dave H, (the other one) That's what I thought too. I presume there isn't a conventional aerial on this car so it's a good guess that the heated rear window is providing this function. If so, there will be a couple of RF chokes to isolate the screen at RF, the only problem is that I would expect these chokes to be near the screen, not under the dash or in the engine compartment. Incidentally I had a Civic with that arrangement for a while, I hated the car for various reasons, but the radio reception on AM and FM was superb. You used to be able to buy one as an add on. It was a grey, plastic tube with red ends and a bracket, plus flying leads for connecting the screen power and the aerial to. About the size of an old style ignition coil. Mine worked very well in my Sierra. SteveW |
OT funny thing
On 11/12/2012 17:06, Harry Bloomfield wrote:
I can assure you I do not what I am talking about. I'm afraid that I don't. Andy -- fx cue skitt |
OT funny thing
Andy Champ laid this down on his screen :
On 11/12/2012 17:06, Harry Bloomfield wrote: I can assure you I do not what I am talking about. I'm afraid that I don't. Andy not = know :-) The point I was trying to make earlier, is that damaged and intermitant rear screen demister tracks can and do cause lots of interference to radio reception, especially if the tracks of the demister are used as an antenna. It has nothing what so ever to do with HV jumping gaps in the tracks, the damage simply needs to be sufficient to make the track intermitant. A very well known issue. -- Regards, Harry (M1BYT) (L) http://www.ukradioamateur.co.uk |
OT funny thing
On 11/12/2012 17:08, charles wrote:
In article , Jonathan wrote: On Dec 11, 3:36 pm, Harry Bloomfield wrote: Gary formulated on Tuesday : Assuming as many do today - the rear screen heater is used as the antenna for the radio and the printed tracks on the glass are damaged, the poor tracks will generate masses of interference when the screen heater is turned on. We have that problem on an ancient Skoda which does have a separate radio aerial. when I think about it, I had that problem on my no-so-ancient Citrφen (only 10½ years). This had a separate roof aerial at the rear of the car. Replacing the aerial cured the problem. It had broken internally - probably because it got bent rather severely when I carried sheets of plywood on the roof bars. We have a roof aerial so I shall check it properly now you have said that. |
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