Gytis1

I just bought a 1984 928s a couple days ago and the auxiliary fan always seems to be on.. Is this normal? Or is there some way i can fix this? Any imput is greatly appreciated

Thanks in advance!

Alan

Turn the AC off...

Alan

longleader

Sounds like a bad temp switch if the AC is off. Well you know you have power, disconnect the the wiring at the switch at the bottom of the radiator and see what happens

Gytis1

Its not the ac for sure

Mrmerlin

if the AC switch is off,
then check that the switch on the front side of the radiator on the driver side is open (IE closed means continuity through both pins)( open means no continuity)
when the rad is cold or that the wires are not touching

Avar928

I have the exact opposite problem, mine never turns on regardless of AC or high engine heat. Already checked the fuses and relay, all fine.

fbarnhill

I have seen them hard wired around the AC switch. Look at the top of the dryer and see if the two wires are plugged into the dryer switch or are stuck together...


Good luck,

Gytis1

Checked the switch and theres no continuity at the switch on the bottom of the radiator. Does that mean switch is bad?

SMTCapeCod

"the" two wires?
Any shot of a schematic or pic?

I'm so bad at electrical......

So is the switch that triggers when the A/C is on at the HVAC head unit?

Mrmerlin

OK the switch should not have continuity when its cold it should close when the radiator gets hot thus passing the power so thats good,
what happens if you have the 2 switch wires removed and the key on,
does the fan still run?

RKD in OKC

Not just the AC switch, make sure the HVAC is not on the far left solid rectangle setting.

brutus

RDK, he has an 84 NOTHING about the fan operation is the same as your car, nothing ! His front mounted pusher (Auxilary) fan is turned on by one of two simple switches. The temp switch on the radiator or a switch on the A/C drier (can in front of rad) . No brains, no tie in to the A/C control unit just a very simple set up where either of the switches can feed power to the fan.
As mentioned due to overheating issues and failing belt driven fan clutches many will hot wire jumper one of the two switches usually the one on the drier as it is EASIER to reach and the fan runs all the time.

RFJ

I don't know if my 85 euro is the same or not but po had put the connections on wrong so there was power to fan all the time. connectors at the top right side of radiator at the switch. hope it helps.ray

buccicone

Worn through insulation on the connector at the high pressure receiver dryer was grounded out on the stay. Repositioning and some liquid electrical tape fixed it. Fan would run with the key even in the accessory position.