1978 OB A/C Condenser Fan help
#16
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
Good luck,
Dave
#17
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
Good luck,
Dave
#19
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
Good luck,
Dave
12+ constant (fused)-------30 RELAY 87------------ condenser fan+
a/c clutch 12+----------------86 85------------ground
#20
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.
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.
#21
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.
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.
Thanks,
Dave
Last edited by j.kenzie@sbcglobal.net; 04-14-2019 at 09:01 PM.
#22
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!
Thanks folks!
#23
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!
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!
#24
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!
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!
Good luck,
Dave
#25
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
Good luck,
Dave
#26
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!
#27
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?
Good luck,
Dave
#29
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.