j.kenzie@sbcglobal.net

Yes, I believe a/c fan and a/c condenser fan are referring to the fan in front of the radiator to give extra air flow to the a/c condenser (and radiator). If you know how to jumper a relay socket, connect 30 to 87 and the fan should come on (ignition may need to be turned on).
Good luck,
Dave

islaTurbine

Thanks. Just seemed peculiar that they would use different terminology for the same component on the very same page.

Ad0911

Hoe van is of to simpel dump the driver switch and purely switch the fan with the radiator thermostatic switch?

j.kenzie@sbcglobal.net

What I did was pull a 12V+ signal off the a/c compressor clutch, and activate the fan whenever the a/c is on. You would need a relay for that or a fan controller.
Good luck,
Dave


12+ constant (fused)-------30 RELAY 87------------ condenser fan+
a/c clutch 12+----------------86 85------------ground

Christopher Zach

If you're going to put in a relay to control the fan, I would recommend using a SPDT relay and connecting it so that the little wimpy relay on the head unit switches only the SPDT relay, which then switches power for the compressor (a pretty heavy 3a load) and the second pole can switch the fan on and off by running in parallel with the dryer switch. That way you get the best of all worlds: The head unit relay will last forever (it's only switching the SPDT relay) and everything will work.

Personally it's spring here and the AC on my 86.5 is working just fine. I do have a SPST relay powering the compressor clutch, the default temp sensor in the dryer seems to work fine to keep the condenser properly cooled.

j.kenzie@sbcglobal.net

That's a great idea. I did that years ago, and it has worked fine. Since the OP was not too sure about connections, I wanted to try and keep my suggestions simple. But, you are absolutely correct. Actually one relay should be able to switch both fan and clutch, but two would also work. You are also correct that a properly functioning a/c pressure switch should let the fan cool the condenser when needed and save the alternator when not needed.
Thanks,
Dave

islaTurbine

Yeah I don’t think my old Paris Rhone is up to the task. I don’t think it’s original to the car but it does look fairly old. It operates the car just fine but I’d worry about putting a constant AC load on her. Besides that, and despite my Borla catback and EGR delete, I’m trying to keep her as OEM as possible.

Thanks folks!

islaTurbine

I took her out for the first time in a bit over a month and was finally able to jumper the temp switch on the receiver drier. The fan immediately fired up and ran at full speed. I did reverse the connecting wires when I reattached them just in case they were mistakenly reversed in the past. We’ll see if that has any impact but I’d say that switch is probably the culprit now.

But as with any old car, when you resolve one issue another tends to arise. Now the passenger window won’t open. The control switch works, the dash ammeter shows a drain when the switch is activated, and I can hear a click inside the door, but nothing happens. Off to another adventure!

j.kenzie@sbcglobal.net

Good news. I would test with a paper towel that the a/c fan is flowing in the right direction. If you hook it up backwards it will act as an obstruction to condenser and radiator and may overheat your car. I did this and I felt pretty stupid.
Good luck,
Dave

islaTurbine

Thats interesting to know. In a previous post on here Ed (post #3 above) mentions that his were reversed which caused the fan to be totally inoperative. You’re saying that reversing them at the receiver drier wouldn’t inhibit operation but would reverse the direction of the fan?

Christopher Zach

Simple. Take out the lift motor, clean it up, remove all the crumbs in it, grease the bearings and reinstall.

j.kenzie@sbcglobal.net

No, I probably misunderstood. Reversing polarity at fan will reverse fan direction. Reversing at R/D I would think wouldn't matter since it's just a switch.
Good luck,
Dave

islaTurbine

islaTurbine

Has anyone else seen this temp switch for the receiver drier? I happened to stumble upon it via PartsGeek and Amazon but it's not listed as a specific item for the 928. It appears that some Mercedes Benz's use it but it looks exactly like the real Porsche part (which I've seen with my own eyes). The Porsche part number is 928-613-131-01 while the manufacturer part number for this piece from ACM is W0133-1628934-ACM.

islaTurbine

Update: The switches from ACM and Santech both look the same, but they don't look like the one available from Porsche.