My daughter and son-in-law just took possession of a repo home that has
a Goodman GMT090-3 furnace. We tried to get it fired up, but the blower
doesn't work. I'm leary about just changing out the circuit board, but
can't seem to measure any power across the motor. I also have
continuity across the start capacitor. It is not the capacitor, but the
wiring. Is this normal? The wiring diagram doesn't really help much so
I don't know where to check the power across which leads. Any ideas
would be much appreciated. We also don't have a manual at all so I have
to wait until Goodman can send me something. Thanks.

Mike D

Mike Dobony wrote:
My daughter and son-in-law just took possession of a repo home that has
a Goodman GMT090-3 furnace. We tried to get it fired up, but the blower
doesn't work. I'm leary about just changing out the circuit board, but
can't seem to measure any power across the motor. I also have
continuity across the start capacitor. It is not the capacitor, but the
wiring. Is this normal? The wiring diagram doesn't really help much so
I don't know where to check the power across which leads. Any ideas
would be much appreciated. We also don't have a manual at all so I have
to wait until Goodman can send me something. Thanks.

Mike D


The cap is not a "start" capacitor, but a "run" capacitor.
It's always in the motor circuit and you are reading the
winding resistances.

Does the thermostat have a "fan on" switch or something
similar? See if the blower will run without gas flame.

Does the furnace attempt to light?
Is there 24V to the board?

Symptoms??


You can go to Goodman site and look for info:
http://www.goodmanmfg.com/Home/Produ...3/Default.aspx
Your model may no longer be listed, so pick one that
looks close (multi-speed drive).
Download a .pdf of the model specs.

But I think you'll be disappointed with the info they give out.
Don't hold your breath waiting for the "manual" to arrive.



Helpful site:
http://arnoldservice.com/Troubleshoo...g_Problems.htm


Jim

Speedy Jim wrote:
Mike Dobony wrote:
My daughter and son-in-law just took possession of a repo home that
has a Goodman GMT090-3 furnace. We tried to get it fired up, but the
blower doesn't work. I'm leary about just changing out the circuit
board, but can't seem to measure any power across the motor. I also
have continuity across the start capacitor. It is not the capacitor,
but the wiring. Is this normal? The wiring diagram doesn't really
help much so I don't know where to check the power across which
leads. Any ideas would be much appreciated. We also don't have a
manual at all so I have to wait until Goodman can send me something.
Thanks.

Mike D


The cap is not a "start" capacitor, but a "run" capacitor.
It's always in the motor circuit and you are reading the
winding resistances.

Does the thermostat have a "fan on" switch or something
similar? See if the blower will run without gas flame.


Already did that.

Does the furnace attempt to light?

It lights fine, but overheats because the blower doesn't run.

Is there 24V to the board?

No idea. There is a 24V spade, but nothing hooked up to it. There is a
red light that stays on.


Symptoms??

Everything lights fine, just no blower.



You can go to Goodman site and look for info:
http://www.goodmanmfg.com/Home/Produ...3/Default.aspx
Your model may no longer be listed, so pick one that
looks close (multi-speed drive).
Download a .pdf of the model specs.

But I think you'll be disappointed with the info they give out.
Don't hold your breath waiting for the "manual" to arrive.



Helpful site:
http://arnoldservice.com/Troubleshoo...g_Problems.htm


Jim

Mike Dobony wrote:

Speedy Jim wrote:

Mike Dobony wrote:

My daughter and son-in-law just took possession of a repo home that
has a Goodman GMT090-3 furnace. We tried to get it fired up, but the
blower doesn't work. I'm leary about just changing out the circuit
board, but can't seem to measure any power across the motor. I also
have continuity across the start capacitor. It is not the capacitor,
but the wiring. Is this normal? The wiring diagram doesn't really
help much so I don't know where to check the power across which
leads. Any ideas would be much appreciated. We also don't have a
manual at all so I have to wait until Goodman can send me something.
Thanks.

Mike D



The cap is not a "start" capacitor, but a "run" capacitor.
It's always in the motor circuit and you are reading the
winding resistances.

Does the thermostat have a "fan on" switch or something
similar? See if the blower will run without gas flame.


Already did that.

Does the furnace attempt to light?


It lights fine, but overheats because the blower doesn't run.

Is there 24V to the board?


No idea. There is a 24V spade, but nothing hooked up to it. There is a
red light that stays on.


Symptoms??


Everything lights fine, just no blower.



You can go to Goodman site and look for info:
http://www.goodmanmfg.com/Home/Produ...3/Default.aspx
Your model may no longer be listed, so pick one that
looks close (multi-speed drive).
Download a .pdf of the model specs.

But I think you'll be disappointed with the info they give out.
Don't hold your breath waiting for the "manual" to arrive.



Helpful site:
http://arnoldservice.com/Troubleshoo...g_Problems.htm


Jim


Quote: " Does the thermostat have a "fan on" switch or something
similar? See if the blower will run without gas flame.


Already did that. "
---------------
OK. Did the blower run or not run??

---------------


Typically, the blower starts after a fixed time delay
from light-off, which is built into the board.

If the board is getting 120V and 24V power, then the
blower (circ) relay on the board is suspect.
Check all the jumpers against the diagram too.

Jim

AHEM! Why not just call the HVAC guy and let him make a proper diagnosis
and repair?

s

"Mike Dobony" wrote in message
news
My daughter and son-in-law just took possession of a repo home that has a
Goodman GMT090-3 furnace. We tried to get it fired up, but the blower
doesn't work. I'm leary about just changing out the circuit board, but
can't seem to measure any power across the motor. I also have continuity
across the start capacitor. It is not the capacitor, but the wiring. Is
this normal? The wiring diagram doesn't really help much so I don't know
where to check the power across which leads. Any ideas would be much
appreciated. We also don't have a manual at all so I have to wait until
Goodman can send me something. Thanks.

Mike D

Mike Dobony wrote:

My daughter and son-in-law just took possession of a repo home that has
a Goodman GMT090-3 furnace. We tried to get it fired up, but the blower
doesn't work.

SNIP

..pdf of the exact model he

http://www.hvacprotech.org/toc/Equip...e%20Manual.pdf

Jim

check for 120v to the motor ??????????????????????????

Mike Dobony wrote:
My daughter and son-in-law just took possession of a repo home that has a
Goodman GMT090-3 furnace. We tried to get it fired up, but the blower

doesn't work. I'm leary about just changing out the circuit board, but
‘can't seem to measure any power across the motor. I also have Ccontinuity
across the start capacitor. It is not the capacitor, but the pwiring. Is
this normal? The wiring diagram doesn't really help much so »I don't know
where to check the power across which leads. Any ideas pwould be much
appreciated. We also don't have a manual at all so I have to wait until
Goodman can send me something. Thanks.p
Mike D

Mike Dobony wrote:
My daughter and son-in-law just took possession of a repo home that has
a Goodman GMT090-3 furnace. We tried to get it fired up, but the blower
doesn't work. I'm leary about just changing out the circuit board, but
can't seem to measure any power across the motor. I also have
continuity across the start capacitor. It is not the capacitor, but the
wiring. Is this normal? The wiring diagram doesn't really help much so
I don't know where to check the power across which leads. Any ideas
would be much appreciated. We also don't have a manual at all so I have
to wait until Goodman can send me something. Thanks.

Mike D

You didn't say if you could read 120V anywhere in the furnace wiring.
If not then there may be a switch mounted somewhere between the
furnace and the breaker.

LdB

On Thu, 24 Jan 2008 14:39:39 -0500, Speedy Jim
wrote:

Mike Dobony wrote:

My daughter and son-in-law just took possession of a repo home that has
a Goodman GMT090-3 furnace. We tried to get it fired up, but the blower
doesn't work.

SNIP

.pdf of the exact model he

http://www.hvacprotech.org/toc/Equip...e%20Manual.pdf

Jim


Thanks. Some fine day I'll need to replace my current old style
furnace. Should I get a new furnace and there's a problem I can
usually troubleshoot any equipment. But this manual let me know what
to look for and will save a lot of digging around.

L D'Bonnie wrote:
Mike Dobony wrote:
My daughter and son-in-law just took possession of a repo home that
has a Goodman GMT090-3 furnace. We tried to get it fired up, but the
blower doesn't work. I'm leary about just changing out the circuit
board, but can't seem to measure any power across the motor. I also
have continuity across the start capacitor. It is not the capacitor,
but the wiring. Is this normal? The wiring diagram doesn't really
help much so I don't know where to check the power across which
leads. Any ideas would be much appreciated. We also don't have a
manual at all so I have to wait until Goodman can send me something.
Thanks.

Mike D

You didn't say if you could read 120V anywhere in the furnace wiring.
If not then there may be a switch mounted somewhere between the
furnace and the breaker.

LdB
With the electronics controlling the entire furnace it wouldn't be able
to fire up without electricity.

Speedy Jim wrote:
Mike Dobony wrote:

My daughter and son-in-law just took possession of a repo home that
has a Goodman GMT090-3 furnace. We tried to get it fired up, but the
blower doesn't work.

SNIP

.pdf of the exact model he

http://www.hvacprotech.org/toc/Equip...e%20Manual.pdf


Jim

That helped. We ended up with a bad circuit board. The motor was good
with straight power running across the leads (hooked up straight to the
power lines), but had no power going to the leads from the board. Ended
up being a bad relay, but since the relay is part of the board the whole
board needed to be replaced. We still can't get the blower to run in
the ON position, but it kicks in on AUTO, so we also have some bad
wiring. Well, just one more wire to fix. We do have power to about
half the house.

Speedy Jim wrote:

.pdf of the exact model he

http://www.hvacprotech.org/toc/Equip...e%20Manual.pdf

Jim

Thank you for posting that link. I've been looking for a manual for my
Ruud.

--
Tony Sivori

Bubba wrote:
On Fri, 25 Jan 2008 02:07:33 -0500, "Stormin Mormon"
wrote:

Sounds like time to call a repair tech. Could be a bad motor, cap, or fan
limit switch. Or some other wiring problem not otherwise specified.

.........and once again Stormy the idiot shows us he hasnt the first
clue in diagnostic ability. Three guesses and you still cant get it
right as the OP posted it was the circuit board.
What a totally stupid fool you are and yet you keep showing us
everyday that you can get dumber and dumber with no problem at all.
Bubba

When I went in to have the cap tested I also got a usable schematic that
described the purpose of the various connections. The one on the door
didn't have much useful info. Also working by flashlight alone, trying
to push in the switch and check for power was a little awkward. I
really do need to get some alligator clips for my meter. I suspected
the board immediately, but without a good schematic it was rather difficult.

On Thursday, January 24, 2008 12:24:36 PM UTC-5, Mike Dobony wrote:
My daughter and son-in-law just took possession of a repo home that has
a Goodman GMT090-3 furnace. We tried to get it fired up, but the blower
doesn't work. I'm leary about just changing out the circuit board, but
can't seem to measure any power across the motor. I also have
continuity across the start capacitor. It is not the capacitor, but the
wiring. Is this normal? The wiring diagram doesn't really help much so
I don't know where to check the power across which leads. Any ideas
would be much appreciated. We also don't have a manual at all so I have
to wait until Goodman can send me something. Thanks.

Mike D

Goodman manual, pdf found at:
http://www.hvacpartsshop.com/Gmph075-4%20Series.Pdf

On Thursday, January 24, 2008 11:24:36 AM UTC-6, Mike Dobony wrote:
My daughter and son-in-law just took possession of a repo home that has
a Goodman GMT090-3 furnace. We tried to get it fired up, but the blower
doesn't work. I'm leary about just changing out the circuit board, but
can't seem to measure any power across the motor. I also have
continuity across the start capacitor. It is not the capacitor, but the
wiring. Is this normal? The wiring diagram doesn't really help much so
I don't know where to check the power across which leads. Any ideas
would be much appreciated. We also don't have a manual at all so I have
to wait until Goodman can send me something. Thanks.

Mike D

I found on 2 different brands of furnaces that through vibration (or defective solder) that the motor relays break loose and arcs until it oxidizes enough not to work. Re-solder is always an option apposed to hundred of $'s for the circuit board.
If you don't have A/C there is usually an extra relay for it on the board. If you could remove it, you can replace the "heat" relay.

On Apr 17, 6:23*am, buffalobill wrote:
On Thursday, January 24, 2008 12:24:36 PM UTC-5, Mike Dobony wrote:
My daughter and son-in-law just took possession of a repo home that has
a Goodman GMT090-3 furnace. *We tried to get it fired up, but the blower
doesn't work. *I'm leary about just changing out the circuit board, but
can't seem to measure any power across the motor. *I also have
continuity across the start capacitor. *It is not the capacitor, but the
wiring. *Is this normal? *The wiring diagram doesn't really help much so
I don't know where to check the power across which leads. *Any ideas
would be much appreciated. *We also don't have a manual at all so I have
to wait until Goodman can send me something. *Thanks.

Mike D

Goodman manual, pdf found at: *http://www.hvacpartsshop.com/Gmph075-4%20Series.Pdf

Glad you found that for him. After all he's been without
heat now for 5 years and the house must be very cold.....

On Apr 17, 7:35*am, "
wrote:
On Apr 17, 6:23*am, buffalobill wrote:

On Thursday, January 24, 2008 12:24:36 PM UTC-5, Mike Dobony wrote:
My daughter and son-in-law just took possession of a repo home that has
a Goodman GMT090-3 furnace. *We tried to get it fired up, but the blower
doesn't work. *I'm leary about just changing out the circuit board, but
can't seem to measure any power across the motor. *I also have
continuity across the start capacitor. *It is not the capacitor, but the
wiring. *Is this normal? *The wiring diagram doesn't really help much so
I don't know where to check the power across which leads. *Any ideas
would be much appreciated. *We also don't have a manual at all so I have
to wait until Goodman can send me something. *Thanks.

Mike D

Goodman manual, pdf found at: *http://www.hvacpartsshop.com/Gmph075-4%20Series.Pdf

Glad you found that for him. *After all he's been without
heat now for 5 years and the house must be very cold.....

Why? Is cold kind of like compound interest? The longer a house goes
without heat the colder it gets?