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« on: September 16, 2012, 12:26:43 AM »
Have just finished a marathon effort on the car and found the short... both of them. The recirculation relays which have been replaced have a different pin out to the original Bosch relays. Pins 30 and 86 were swapped so that was grounding the output. Also the wires around the compressor are a train wreck with massive chunks of missing insulation.
With the compressor disconnected I went to work on the relay wiring. Now I thought I had already fixed the pin out issue a few days ago, but my mate was helping me this time and realised I had somehow swapped the pins around in some random configuration that didn't make any sense. Since then I have learned much more about relays and what these one are for. So while he was working on the connectors I took out a pen and paper and figured out the wiring from scratch. They are basically wired up the same but with 87 and 87a swapped so that when the power is cut the polarity reverses and the recirculation flaps close.
We had been at it for a while and were rigging up fuses with copper wire as we were burning through them too fast. I came back with my paper results and had a very different answer to my friend who was just using trial and error. I pointed it out to him and he decided to test his next possibility, as he was about to when I walked in and melted the wiring in seconds.
So after we had replaced all the melted wires (it was only really 2 once we examined the damaged). We wired it up my way and it's all good. Somehow even got all the blower speeds working again, I was only getting high speed but had put off the resistor replacement until I had this sorted.
Now the air con. This has been out of action for a long time so I wasn't sure it would work at all. So we unplugged the pressure cut off switch and the compressor was already disconnected. Bridged the switch wires and tested the compressor power to make sure there would be power if the switch allowed it. Then plugged the switch back in tested again, no power. So the system is too old to turn on without some expert involvement. The wires have been safely isolated and the air con will wait for me to win the lottery.
Also I have reconnected the aux fan (after some testing) without the resistor and upgraded Fuse #3. Just in time for Summer.
While we were in the dash also rewired the stereo, a PO had some very strange wiring in there so we pretty much started from scratch and redid it all which also included hooking up the electric antenna. So now I can listen to the radio and with all the speaker channels and all the speakers working, I can even hear it.
Thank you all for your input. I'm getting some rest then starting on the stuttering wipers....
DesktopDave - I do have an ETM (assuming you mean manual). I did unplug the aux fan and test the hot water sensor after reading your post.
DanOKC - From your list, it was only the recirculation relays. We had wandered off into no-mans land testing electronics as we were at a loss, after reading your post I realised we should go back to the relays and look again.
Cheers
Ed