F R O S T Y said:hi again alex, today i disconnected the stereo and i havent had a problem at all, weird huh? one thing for sure is the car began to jerk as i turned the volume up, the head unit switched itself off and the clock was reset, it all happened so quickly and hasnt happened since i disconnected the head unit wires, i've now connected the yellow wire from stereo to brown provided by fiat, and black from stereo to black provided by fiat, havent yet connected the 12v switch wire yet, i've had a look at the wires on my old heater matrix unit to get an idea i'm assuming they will be the same on my new unit but will have to double check this obviously and i can see these colour wires a red wire, a plain blue wire, and a second blue wire with a black stripe on it. Is it the blue and black one i should tap into???
F R O $ T Y
Umm - make sure you tap into the wire going into the switch, not the ones coming out to the fan... otherwise your stereo will only work with the fan turned on - fun, but the novelty wears off.
According to wiring diagram 46 (Haynes page 14.38) the 1372cc Turbo i.e. model has a red/green wire to the radio that provides the permanent live supply. The diagram also shows front speaker wiring (Red/black and white/black left, black/violet and pink/black right - I have no idea how they choose these colours...)
The heater fan switch gets its switched-live supply from a wire coloured grey/blue.
The red/green wire to the radio is actually connected to the heater I believe, it's shown as the first wire of plug B (the other wire is the black earth wire). So to do a tidy job, you can probably add the switched-live connection at the heater and run the wire with the other two.
If you have a Mk1 (which I don't think you do), then it's all different. Page 14.15 has the relevant wiring diagram, mislabelled as 'Wiring Diagram 22' when plainly it is actually '23', initially confusing. Anyway there is one brown wire marked 'radio', and the heater fan switch is powered by the blue wire (this blue wire also runs to the roof-mounted clock, so you should be able to pick it up at a convenient connector near the fusebox.) That is, if you have a Mk1 - otherwise please disregard
As far as the electrical problems that you were/are having, I suggest a separate earth to the head unit - don't rely on that existing connection - head units today have a far greater power usage than they did in the late 80's (when 8W/channel was on the generous side...) and since the stereo power supply presents an inductive load, strange things can happen if the earth is not good enough.
It gets even more exciting if you have a separate amplifier (e.g. 300W RMS) and an inadequate earth for that...
I was having head unit problems, fuel gauge problems, front side lights glowing dimly, that sort of thing.I decided to post this on the forum since your PM storage-space was full, and I didn't feel like discarding my typing
Hope this helps,
-Alex
