Fans Not Working

[TIMMY]

HI GUYS, HELP! I have a 97 boxster, I just took the car out of storage, while driving home i noticed the temp. passed the 180 mark " passed the 0" I pulled over to check if my fans were working. NO FANS RUNNING! just the one in the rear. My coolant was at the full mark. I turned the air on and the fans went on . What do you guys think it is, I checked my fuses there ok. I started my car in the garage just to see how hot it was going to get before the fans come on, went passed 180, still no fans? Fan sensor? Fan relay? thanks

[nixonad]

I would definitely check the relays first, although I suspect you have a bad resistor.

To check the relay, the fan relays (there are two for each fan, four total) are the same as the horn relay. To check mine I just unplugged them and then tested them one by one by plugging them into the horn relay socket and honking the horn.

The problem I had was that my fans would not come on unless the AC was on. You'll notice that normally the fans should be on low and then go to high speed when you turn on the AC. Mine would be off, then on with the AC. There is a module in the power lines going to the fan that changes the resistance and therefore the fan speed. These can fail due to moisture and old age, and when they do, symptoms like what I got happen.

The part is called "series resistance" and you should be able to find it on the Auto Atlanta parts page. You can also email Sunset and they can help you find the part. If I recall it was about $80-90 and it comes with wiring to replace the old one. There is one of these resistors on each side of the car, on the underside of the bumper just behind the fan.

However, if you do have to replace it, it's probably easier (unless you have the front bumper off) to cut the old one out and solder the new resistor in place. Do a little searching on here or on PPBB.com for fan resistors and you can find more.

[TIMMY]

I would definitely check the relays first, although I suspect you have a bad resistor.

To check the relay, the fan relays (there are two for each fan, four total) are the same as the horn relay. To check mine I just unplugged them and then tested them one by one by plugging them into the horn relay socket and honking the horn.

The problem I had was that my fans would not come on unless the AC was on. You'll notice that normally the fans should be on low and then go to high speed when you turn on the AC. Mine would be off, then on with the AC. There is a module in the power lines going to the fan that changes the resistance and therefore the fan speed. These can fail due to moisture and old age, and when they do, symptoms like what I got happen.

The part is called "series resistance" and you should be able to find it on the Auto Atlanta parts page. You can also email Sunset and they can help you find the part. If I recall it was about $80-90 and it comes with wiring to replace the old one. There is one of these resistors on each side of the car, on the underside of the bumper just behind the fan.

However, if you do have to replace it, it's probably easier (unless you have the front bumper off) to cut the old one out and solder the new resistor in place. Do a little searching on here or on PPBB.com for fan resistors and you can find more.

Thanks nixonad for your help! The problem you had seems to be the same as mine. Going to take a look.