Fan will not turn on

[Penz]

...changed the thermostat......fan still did not turn on.......then i replaced the relay switch........still no fan........could it be temperature sensor? anybody have their fan stop turning on ?.......i hot wired the fan and it worked, so i believe it is still good......thanks in advance for your suggestions......

 

[Roc87]

Need to check the fan relays, there are two, a high speed & a low speed. Make sure you have a constant 12V+, a key-on 12V+, and check for a ground when you believe the fan should be on. The relays have 12V+ in, 12V+ out to fan motor, the 12V+ keyon (smaller gauge wire) & the ground turn on lead. IIRC it should be a green wire that is the ground turn on lead.

Just ran into this in my elcamino, and I ended up building a complete new wiring harness for the fans:frown:

 

[USA_muscle]

having the same problem. Fan works if hot wired. Upon checking the red wires, I have power to the delay relay (red), but not to the high speed (red). I also have the 12V key on power (ECM/SOL fuse I believe) in the small black/pink wire. Checked the fuses and they are all ok. So if I am reading the wiring diagram right, somewhere between the FUSIBLE LINK and HIGH SPEED RELAY I have a break in the power.? I really don't have the time right now to go over the wiring so would it be ok to splice the delay power over to the high speed power? Technically the fusible link is still working if I am getting power to the delay realy and I would just be by-passing that wire. Am I looking at this the right way or am I off the mark? By the way, where is the fusible link located?

 

[USA_muscle]

One more thing. I was also considering running a hot wire on a switch for the fan in case I have problems again. I was going to run a 10g wire with a 30amp inline fuse to a 30amp switch in the car and then to the fan power wire. would that be ok? TIA for any help.

 

[DailyDrifter]

One more thing. I was also considering running a hot wire on a switch for the fan in case I have problems again. I was going to run a 10g wire with a 30amp inline fuse to a 30amp switch in the car and then to the fan power wire. would that be ok? TIA for any help.

Dont send the power through the switch. Put the switch on the ground side of the circuit so you dont burn the contacts out prematurly(sp?). Did you replace the fan switch on the intake manifold?


OP check the fusible links going to the starter (Red wires). If they are good run the fan off the battery so you know the fan motor is Actually working and not burned up. I think Roc87 brings some good info with the relays.

 

[bmackinnon]

Go here for comprehensive troublehooting of your TR fan (non)operation...

Vortex Turbo Buick Performance

click 'troubleshooting', then 'fan circuitry'....

That should get you going...

 

[Penz]

....thanks for the valuable information....now its just a matter of getting in the garage while watching 3 lil ones!

 

[Guess]

Thanks for the vortex link. I'm going through the same thing. I know the fan works, but the troubleshooting article will help immensely.

 

[Guess]

Fixed!

Using that article, I found no constant power to the relays when the key was off. I checked the post on the starter and the connection had gotten brittle and the wire broke off.

 

[DailyDrifter]

Glad to hear that. When I got my chitbox put back together I had the same problem, and I found that the fusible link wasnt connected to the post on the starter.