Location of diode in a/c wiring circuit

**sageadvice** · 03-09-2018, 04:53 AM

The supplementary fan for engine over temp/air conditioning on is no longer running when the a/c is on.

All the a/c works just fine, I can see the clutch is pulled in and the air gets nicely chilled.

On tracing back I see no volts at the fan motor connections, no volts on the supplementary fuse, no volts on the coil input (port 86) to the supplementary fan relay, although that relay has a 12 volt feed and the earth and fuse connections are good.

The connections under the fuse box appear good.

So next in line is the diode which sits between the compressor clutch feed and the relay input.

Does anyone know where there is?

I'm guessing somewhere over by the compressor but it could be anywhere between the compressor and the relay or even the a/c switch and the relay - the T in the wiring could be anywhere.

**cgifool** · 03-09-2018, 12:41 PM

I think it's built-in to the compressor end of the terminal on the a/c clutch wire running from inside cabin to the a/c compressor.

see part #4

http://www.realoem.com/bmw/enUS/show...93#61311358265

**2002jm** · 03-09-2018, 02:43 PM

It should be on the driver's side right near the headlights; well behind the headlights. It is just a small black plug in. I have one if you need it; new too

jm

**82Kashmir** · 03-12-2018, 09:27 AM

Had the same problem last year I remember the aux fan fuse socket was the problem cleaned it up and the aux fan came on. Check all connections for corrosion.

**sageadvice** · 03-15-2018, 06:02 PM

Thanks. I have not had time to look closely at this but I can see the wiring heading off behind the headlamp cover. So it looks like it is in there. Makes sense as the thermo switch is over there too. Thankfully, easy to access, not buried somewhere under the dash.