Engine got real hot approx. 260. Ac will not turn on fan. Applied 12v to fan, runs. Bypassed coolant temp switch, fan does not run but relay energizes. I don't have the wiring schematics yet so i am still in the dark. Any suggestions?

 

i assume this is on the 86 LG4? did you ground the plug from the fan switch to see if anything happens?

which switch/sensor did you bypass? the one on the driverside or the one on the passengerside?

If you did that and the relay energized, there is a break between the relay and the fan, could be a ground. there are fusable links in the harness to the fan, maybe one went bad?

 

When I grounded the plug (green wire) from the fan switch is when the relayed energized.

I bypassed the coolant switch (green wire) on the pass. side.

That's what I was thinking there was a break in the wire. I was unsure if the relay was the last component before the fan. Now I just need the wire scems.

 

well im still a bit confused

the sensor in the head on the driverside is the temperature sensor that works the temp guage in the car, it hse nothing to do with the fan.

the sensor in the passengerside is the fan switch, it controls the fan. If you ground that plug, and you have power in and out of the relay, then there is a break in the wire.

 

426 Wedge, pm me your e-mail address and I will send you wiring diagrams for your car. I have some on a CD. Also, with your e-mail tell me your car specs. Make, model, engine, TPI or TBI etc. If you want the diagrams I will get them to you later tonight or tomorrow. I was there in the day of the "426 Max Wedge, even got to drive sometimes. Where did you come up with the name?

 

The pass. side is the one I bypassed to check the fan, not the drivers side. The drivers side is used by the ECM.

 

PM sent.

 

How do you know the relay energizes?

Just because it clicks doesn't mean it's working, blown relays still click. Remove the relay to expose the 5 female terminals inside the connector. You will see two thin wires and two thick wires leading to it. Use a paperclip to jump the two thick wires (should be red and black, do it quick as to minimize arcing which can lead to scorching on the connectors which can lead to more blown relays) and the fan should come on. If it does the relay is blown. If it doesn't then there is a break in the wire.

 

That was it, bad relay, the fan came on. Appears someone installed a Omron relay and connector before I had the car. This relay is obsolete.