Jwolf427

I noticed today that my front oil cooler fan (front passenger side) does not come one when the oil gets to operating temperature. I jumped the relay to see if the fan was faulty, but it turns on. Could this be a bad ballast resistor or the relay? Just to be sure I am thinking about changing both the relay and the resistor. Any one have any suggestions?

P-daddy

Low speed fan doesn't come on until about 9 o'clock, IIRC.

Jwolf427

Thanks for the reply P-daddy, but the fan does not come on even when the needle reaches a little over the 9oclock mark.

justin-in-athens

switch the two relays in the front of the fuse box. They are identical and usually have pink stickers on the top. One is for the oil cooler, the other for the AC. If the cooler functions after the switch, you will know it is just the relay.

If it is not the relay, it could be the fan itself, the CCU, or the temp sensor located inline just above the cooler.

NYC993

Mine doesn't come until quite a bit pass 9 o'clock.

To test the fan you can open the relay and manually switch the fan. That's how you can also test if your resistor is dead (lack of low speed fan setting).

You can also disconnect the temp sensor near where oil pipes connect to the cooler (near headlight opening), but it's quite hard to disconnect through just headlight opening. Once disconnected, the fan should stay on high.

Jwolf427

I tested the fans by jumping the relays and they both work. Could the relay and the ballast resistors be the reason they are not activating. The rear blower fan turns on, but in intervals when the car is turned off.

NP993

IMHO the factory fan settings turn the fan on at too high an engine temp (this was done for emissions). One of the first things I did was install a manual fan switch. Even in the hottest traffic my engine never sees over 200F. Air cooled motors like to run in the 180-190F range, not well into the 200's like the factory setting.

Jwolf427

I found the write up. Thank you

NYC993

Could be relay not working...not sure how to test it, without warming the engine and trying to observe low speed and then high (and they are hard to tell apart). And it's not that easy to get engine that hot without idling for a long time, which I would avoid.

Perhaps there is easier way to test relay with AC fan and engine off.

Did you have both low and high speed (relays have two settings)? The resistor will only impact the low speed (i.e. you would not have low speed with bad resistor as the current doesn't flow though it).

JB 911

it's unclear from this if they both work at both speeds, hi and low like nyc993 says. If not, look for a thread from user bruce7 on testing the operation.

I agree. I believe the low speed setting is approx. 239F. I've never seen this done but you know somewhere within the ccu software there is a limit somewhere that says 239 on. All it would take is someone with the correct software to change that 239 to a 190-210 number and I think all would be good. I did the override too. It's really nice to be able to idle or be in stop and go traffic if you have to and be able to keep the oil temp within check.

Jwolf427

I jumped the relay for the oil cooler and only get high speed setting, so I am assuming that my resistor is bad. Also when I turn on my AC, the fan ont he driver side does not turn on. Does this mean my relays are bad?

P-daddy

As soon as you turn on the AC, low speed fan should be on instantly. Replace your ac series resistor.

Jwolf427

I am getting low and high speed when I jump the relay, so the resistor was bad. I took the car out today and get her nice and warm, but the oil cooler fan does not turn on. Could this mean my temp sensor or CCU is bad?