OK, guys and gals. I'm really depending on your help. I've been fighting with my aux. fan for weeks now with no results. I cannot get the aux. fan to turn on when the a/c is turned on. First, I checked all the wiring. Next, I checked the relay. I also checked the fan motor itself. Finally, I checked the fan switch that screws into the a/c line. I know that it has to be related to the switch somehow, but cannot seem to identify why the switch will not work. With the a/c on, and the plug removed from the switch, you can use a jumper wire between the two terminals, and the fan will turn on. I do realize that the a/c must have the proper pressure in the line for the switch to work. I've replaced the switch twice thinking that it had to be the switch. Still no luck. I do realize that aux. fan is also tied into the temp. switch that is located on pass. side head, but I'm not excited about the aux. fan not coming on until it reaches 235 degrees. Especially when warmer weather is just a few months away. Any help would be greatly appreciated.

 

Got to be a bad connection. bend something to make sure there is good contact.

 

i had a problem with my aux fan comming on, couldnt for the life of me figure out where the problem was, i went over everything like 5 times. finally i bypassed everything and put in a manual on/off toggle switch for my aux fan. works like a dream.

 

Don't ya just hate when that happens? I was ready to do the same, but I finally got everything to work automatically. I ended up rewiring the whole fan circuit....everything new. Wire, relays, sensors, the whole bit.

 

Hi, first try swapping the primary and secondary fan relays,
relays die alot, this is a simple way to test, you should still see primary fan run when engine's hot , and secondary fan work.

ok if not relay, then we need to look at why relays not getting
turned on, there are four wires at fan relay,

(with ignition on, engine off) two of the wires should have power to the relay, orange (E terminal) and bown ("D" terminal)

the thick black and red("A"termial) =power to fan

AND the little gray wire ,("F" termial) this is the ground telling relay to work, ground this wire, if the fan runs, look at for
failed A/C pressure switch(located in rear of compressor)

Note: this switch needs to see a/c pressure at 233psi, before turning on, no refridgerant no pressure no fan working,

STILL NO FAN? lastly hook up a test light at fan location and make sure you dont simply have a bad fan motor

 

I usually have to turn my ac on in order to get my fan to turn on. Is this normal?

 

have the dual cooling fans in my car and unfortuneatly when i bought the car neither were in operating condition. So me and my buddy went thru everything inch by inch and rewired and rewired again and tried this and that and we could only get 1 fan to kick on and only when the AC was on. So right now im rigged to a switch to turn them on and off from inside the car. I gave up.