I'm converting the front headlights from gen 1 to gen 2, and at the same time I'd like to convert the cooling fan setup from the 2-speed to a 1-speed, since I have the complete front harness from an 87. Has anyone done this? It seems simple enough at the engine side: Cut the two wires off the fan switch, use a newer type fan switch and reuse only one of the wires. But at the front, do I just use 1 of the wires, or should I replace the fan motor, too? Maybe the connectors are different? The new harness includes the new style fan relay.

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1984 Fiero SE

I gave my buddy an entire front harness, it plugs in right to the left of the master cylinder.

Might have to take your hood off to get to it.

I did this a few years ago on my 84. I had a bad 2 speed fan and found it way cheaper to replace it with a new 1 speed motor. I had to change the fan mount for the 1 speed motor and found a 1 speed relay and connector at the u-pull it and got Rodney Dickmans low temp fan switch. I matched the wire colors up and on the new used relay connector and was back in business.

[This message has been edited by johnt671 (edited 05-27-2008).]

The two speed fan system has two sensors. See the notes in my cave. I think all you need back there is disconnect the red plug. Not entirely sure.

If you plug in the 1 speed harness up front, and assuming that you don't need to move any terminals, the harness takes care of it all for you.

Don't cut anything in back... You may want to move a pin on C100 up front so that the fan comes on at a lower temperater. The 2 speed turns on the low speed circuit sooner than the normal 1 speed sensor.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top of every forum page...)

Just did this on the car I bought. Guy I got it from picked the car up without a fan. He had is neighbor install an aftermarket 1 speed, but wired it to a switch. I found the old harness under the drivers light. There are 2 wires, a Blk/Red and Blk/Pink. I took two 4" sections on 10 ga wire and put male spade connectors on one end of each, and the shrinkwraped the other ends together. That end connects to a 20-amp inline fuse (just cause) and then hooks to one of the wires on the new fan. The other off the fan is grounded. Take the two spade ends and stick one in each port on the harness. Now, the fan will come on when its suppose to, but it ony has the one speed. To make it a two speed all I have to do is run a resistor inline of the Blk/Pink wire, but the fan is quiet enough I really don't care.

quote Originally posted by RWDPLZ: I'm converting the front headlights from gen 1 to gen 2, and at the same time I'd like to convert the cooling fan setup from the 2-speed to a 1-speed, since I have the complete front harness from an 87. Has anyone done this? It seems simple enough at the engine side: Cut the two wires off the fan switch, use a newer type fan switch and reuse only one of the wires. But at the front, do I just use 1 of the wires, or should I replace the fan motor, too? Maybe the connectors are different? The new harness includes the new style fan relay.

I just did this with parts from DarkHorizon. I did it on my Indy, so shh...
I'm sure the purists will be pissed, but the two-speed motor is a POS. I took apart my two-speed motor because it made a grinding sound. I found that the magnets had come unglued from the motor can and were grinding against the armature laminations.

The motor plug style doesn't match up so you might as well get the newer style fan motor anyway.
Just grab the shroud and motor from a 85+ car with AC (it actually makes a difference, non-AC cars don't have a full shroud)

If you are using the full front harness from the newer car, you'll probably have to remove the hood to snake it across and around the front compartment.

*****I set mine up so the relay comes on at the lower fan temp.*****
All the stars are so you will take note of what I am about to say: EVERY 1984 two-speed temp switch I have had in the last 5 years has been BAD, save one I pulled from a junkyard. If the relay goes bad, it tends to burn out the temp switch. Check yours before you trust it to protect your engine.

If you find your two-speed switch bad (as mine currently is in my Indy) then there's an ideal solution.
Get a squeeze-to-release 1 pin pigtail used for the temp switch on the V6s (as well as a lot of other GM cars) and go order a new fan switch for an 89 Turbo Trans AM. This fan switch is supposed to be a 209 degree piece and carries the aftermarket part number SW555.
Splice in the pigtail and you're good to go.

So the newer fan motor will not bolt up to the 84 shroud? I'd rather just buy a new motor if I can just replace it, Fiero parts are not easy to get around here. I would also replace the switch and connector at the engine as you said, the switch is real expensive and bound to be hard to get in the near future.

Not only does the newer motor not bolt up to the old shroud, the newer motor won't take the old motor's fan blades either. You'll see the difference when you have them apart. The diameter of the motor is much different and the mounting method is different. The fan on the old style uses three screws and screws into the armature itself, and the center shaft of the motor is stationary. On the newer style fan, the motor shaft turns (like 99% of motors) and the fan mounts to that in a different fashion.

I wish you would've said something a few days sooner, I was just up there Saturday and Sunday checking out Black Star Farms and Leelanau Cellars doing wine tastings and we went to Old Mission Light and Grand Traverse Light.

Kurt

If I'm not mistaken, the 87 did not use a fan relay, and the 84 did, so your 87 front wiring harness may not be very plug n play.