Coolant fan problems?

[icepenguin66]

I have my fans wire in parallel and since I decided to use the 1.8 waterneck for my 1.8 swap, I took the wire from the temp sensor and ran it to a switch in the dash then to ground to complete the ground circuit. Today the fans decided to quit working and almost overheated on me! I checked all the connection and the light on the rocker switch comes on showing a completed circuit and all the fuses are good. There is no way the coolant fan motor is toast cause it is practicaly brand new. Is there a relay the fans run through that I should check? I'm lost after all that!

[channelmaniac]

Yup. Page 1 of the 90 wiring diagram shows:

COOLING FAN RELAY (IN RELAY/MAIN FUES BLOCK, RIGHT REAR SIDE OF ENGINE COMPARTMENT)

It also shows:

COOLING FAN FUSE 30A - HOT AT ALL TIMES

RELAY (IN RELAY/MAIN FUES BLOCK, RIGHT REAR SIDE OF ENGINE COMPARTMENT)

The BLK/RED wire goes from the fan fuse to the relay. Come out of the relay as a YEL wire to the cooling fan motor. BLK wire comes from there and goes to the "JOINT CONNECTOR (REAR OF LEFT FRONT FENDER)" which is the multi-wire ground under the brake and clutch master cylinders.

Check each wire for melting/burning. Now for the good part... ENGINE FUSE 1 15A, FUSE BLOCK (LEFT SIDE OF I/P), is labeled HOT IN RUN OR START and connects through the MAIN RELAY (IN RELAY/MAIN FUSE BLOCK, RIGHT REAR SIDE OF ENGINE COMPARTMENT) before connecting to power the coil for the cooling fan relay which is in turn connected to ground through the "WATER THERMOSWITCH"...

Yeah, I'm using a lot of caps, but hey - all the items in the wiring diagram are written in all caps.

There's a tap off of the ground leg which goes to the Air Conditioning System A/C relay to allow it to turn the fan on as well.

You have to troubleshoot the following:

1. Are you getting power to the motor? If so, check the ground wire. If it's good then the motor is fried.
2. If you aren't getting power to the motor then swap the relay.
3. If that doesn't fix it are you getting power to the relay? Check the Engine Fuse 1 (although I'd think the car would be dead without it)
4. Check the output of the relay, do you get 12v?
5. If you aren't then check the grounds for a toasty wire or bad connection.
6. If you are then check the wires between it and the cooling fan motor for a toasty wire or bad connection.

Running the fans in parallel could be asking for trouble, depending on how you do it. If you just connect the two hot leads for the fans together then you are asking for it. It will force the relay and the wiring harness to power both fans which could cause things to cook.

RJ

[MadMonkey]

Aren't you guys up a little early?

[icepenguin66]

Thanks for the help RJ, since you are so close I may need to drop by! At the parents place right now and my father tried to help. I guess I need to check the relay. The hot wire from the harness going to the coolant fan does not have voltage. We tested everything else and all seems well. For a temp fix I have a jumper wire from the power source under the hood directly to the coolant fan since the motor says 12v it shouldn't be a problem as far as cooking a wire or fuse etc.

* Oh yeah, according to your post I am asking for trouble as far as the parallel fan wiring! How should I be doing it?

[channelmaniac]

Well, Chris came by tonight and we fixed it. It was the relay. The current draw from two fans was too much for it.

The guy I bought the engine/transmission for the spec from gave me some extra parts and a relay was one of 'em.

I have the old one and will post pics of the burnt contacts later tonight.

RJ

[icepenguin66]

Well, Chris came by tonight and we fixed it. It was the relay. The current draw from two fans was too much for it.

The guy I bought the engine/transmission for the spec from gave me some extra parts and a relay was one of 'em.

I have the old one and will post pics of the burnt contacts later tonight.

RJ

Yep, thanks again for the help and the free relay! Much appreciated!