[V8] A/C electrical circuit

[Gunter]

Anyone know of a way to check if an A/C relay is faulty (other than replacing with another relay)?

My compressor does not come on BUT if I bridge the relay terminals 30 and 87 it does no problem.

There are no error codes when I do a system check on channel 17 on the Head Unit.

I thought that it might be the under-the-dash A/C controller module because I had a front windshield leak that caused water damage in the area............whole relay/fuse box had to be replaced by Keith of Audi Connection due to corrosion...........BUT the A/C controller box and its contents look OK.............

The inside of the A/C relay itself also looks OK...........no signs of corrosion or other problems


Again, anyone know of a good way to test the relay to see if it's faulty..............could I run a small current across it to see if it switches on? (how much voltage?)

One thing............the power lead to the relay.........which is #87a............only has 0.06 Volts being supplied to it when the car is running and the A/C system is on (again, the only that does not seem to be turning on is the compressor UNLESS I bridge the circuit...........then it works quite nicely)  I don't know if that's too low to switch the relay.............and if it is too low.............what could be causing it to be too low?


Hoping to sort this out..............Spring has finally arrived...............the leather seats will be far too cozy if I don't get the A/C up and running.

Gunter 
1990 V8 140 000