"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)