1G radiator fan won't turn on

**scheides** · 04-20-2008

Having radiator fan troubles on the 1G. Checked the fan, it spins if I wire 12v to it, no problemo. This is the stock fan on the passenger side, wired into the stock plug. What is it that makes this fan spin when the car gets hot, is it the ecu, triggered by the lower temp sensor? Sensor feeding the gauge seems to work just dandy, have not hooked up a logger to verify the other sensor is working. I have not tested the voltage at the plug, either. Just wondering if anyone has any suggestions to get this thing spinning!

AwdGSX13 · 04-20-2008

hey, im not positive but isnt the right side wired in for the a/c switch? I thought it was the secondary but maybe im wrong.

edit *Passenger side*

**scheides** · 04-20-2008

Side question, anyone know a good place to just hardwire the fan on when ignition is on?

**Kracka** · 04-20-2008

He is talking about the fan on the passenger side of the car which is the main cooling fan.

AwdGSX13 · 04-20-2008

^ Thats what im talking about, thats where mine was wired and it only worked with the A/C switch on...

**Kracka** · 04-20-2008

Maybe i am nuts, but I think the A/C fan is on the driver's side...its been too long!

**scheides** · 04-20-2008

A/C fan was wired on the driver's side as far as I know.

AwdGSX13 · 04-20-2008

i dunno maybe its just been awhile since looking at it.. lol

**scheides** · 04-20-2008

Swapped the relays and checked the fuses, still no go. I'm wondering if the pass side one *is* the a/c one. I'll try that tomorrow.

turbotalon1g · 04-20-2008

wow. sorry to hear about your troubles, but you guys haven't gone crazy, the pass. side fan is the main fan.

Should turn on at about 203-206F

**scheides** · 04-20-2008

It's controlled by the ECU, right?

**Halon** · 04-21-2008

I believe the stock BCS is 12V that's comes on with the ignition. Not sure how well it can handle a fan though.

I believe the fan is simply controlled by that switch that is threaded into the bottom of the radiator on 1G's. Kyle mentioned something about being able to buy switches that thread in, but switch on at a lower temperature. Have you tried putting in a new switch? That may be worth a shot, and shouldn't take too long to swap in.

Also, just a dumb question, but are you overheating or anything? Do you know that the fan isn't running when it should be running? If it's not even getting up to the correct temperature where it should be turning on at, the fan won't kick on.

And yes, the passenger fan is the MAIN fan.

Kevin 1G Drummer · 04-21-2008

There's a seperate temp sensor for the fans. It's on the lower radiator tank on the left side if you're standing at the front of the car facing the engine. The sensor is probably bad.

**scheides** · 04-21-2008

Ya the car is def getting up to temp, and even overheating. I'll round up a new switch after I test for voltage coming out of the plug and the a/c thing.

xveganxcowboyx · 04-21-2008

Kevin has got it. There is a temp switch below the main fan. It's a small screw in type near the lower passenger side radiator mount.

I believe the plug for the ac fan is the same. You could plug it into that and keep the ac switch on as a temporary fix. You could also use the AC switch and drivers side fan wiring as a trigger with a relay off the battery. Then it would be controllable and could operate all the time. As an added fail safe, I'm pretty sure the AC fan comes on if the temp gets too high so even if you forgot the switch it would still come on eventually.

*edit* if anyone has a link for the lower temp fan switch I'd love one. I'd prefer it to come on in the 190 - 195 range.