Another Cooling Problem
 

Heya fellows been awhile since i posted but i could use a little help. I'm having a problem where i my high speed cooling fans won't come on.

Things i have tried:
I jumpered the 3 pin connector going to the thermoswitch and i can get the fans to come on at low speed by jumpering pin 2 and 3 but when i jumper pins 1 and 3 nothing happens (high speed fans should come on). Replaced the relay with a know good one didn't work. I even Ohm'ed the fan resistors and they checked good. The only thing i can think of left to do is jumper the relay but i'm not sure which pins turn on the high speed fan or if its even possible.

Any idea's or help would be very greatful, summer is approaching and i have put this off long enough. By the way i did search the boards and did find someone having the same problem but he never posted if he fixed it or if it was every resolved.

Thanks,

Kenne

Does your vehicle have ac? If so do both fans come on when you turn it on? Swap the wires on your thermoswitch.

Yea the AC works fine just no high speed fan when i jumper the thermoswitch. I'll try swapping the wire and see what happens.

Thanks for responding Todwic.

Forgot to mention that the high speed fans do come on with the AC on.

If the fans come on with the AC then the thermo switch is bad. As I remember it the only part that is bypassed by the AC switch.

Hrmm i thought by jumpering the connector to the switch you were bypassing the thermoswitch which was taking that out of the equation. So if the fans did come on when you jumpered it it was your thermoswitch and if they didn't it was your relay.

Well you know it probably wouldn't hurt to replace that thermoswitch it only $20 and a bit of time. I'll give that i try this weekend and let you know what i find. Thanks for the reply Roger.

Kenne
91 944S2

I agree with Roger. and you already replaced the relay.

Cooling fan roubleshooting procedures, may be of some help.

http://www.clarks-garage.com/

FYI for those troubleshooting coolant problems. I fixed my problem by replacing the thermoswitch and flushing the coolant. Seems to be working right now but we haven't had any hot days yet so time will tell.

Just a heads up i don't think clarks procedure on troubleshooting the fan is 100% correct for 86 and up cars. Since even after i replaced my thermoswitch the low speed fans would not come on but they do work when the car starts to get inbetween the 1st and 3rd bar they come on. I tried his jumpering method on both of my cars and and could only get the high speed fans to work and yes both relays work =)

Kenne
91 944S2
86 944na

Congrats feels good

I was told by the PO to leave the A/C on while daily driving to keep the temp down, is this recommended? Keeps both fans on?
Thanks!

Binky,

I wouldn't recommend running around with the AC on all the time you shouldn't have too if your fans are working correctly. Try clarks procedure and see if it works for you it might be as something simple as the relay is bad.


Kenne
91 944S2 looking to buy a 968......

make sure that there is no air in the system.