Does anyone know if the 84 - 86 headlight motors can be re wired to work on an 87 - 88 harness. I don't want to swap out the harness, just modify the older motor to work on the newer harness. The newer style motors are in short supply here but 84 and 85s abound. Does anyone have pics of the newer motor innards? How about a wiring diagram for the inside of the motor. I need to know which wire goes to what brush etc.

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84 2M4

Save your self a lot of trouble and get the 88 harness it is not worth the hassle.

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85 Fiero (Savage)
345-HP/5SP 4.9 Cadillac.
88 Modified Cradle
11.2" Zettner Brakes
Custom Coilovers
Flowmaster 80'Series Muffler
Keith Dorton 500cfm 2 Barrel Carb#0-8583
Edelbrock Signature air cleaner
Edelbrock-70001 3stage NOS kit.
Mallory HYFire IV Ignition system
70's Transam side scoop
Warber hood scoop
B&M Pro OilCooler

I agree.....lots of wiring differences. It's gonna be a real pain to change. Before 87 has 5 relays. 87 up has a module to actuate the HL's.

Phil

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GTDude
OVER 25 years GM experience

quote Originally posted by GTDude: ..Before '87 has 5 relays. '87-up has a module to actuate the HL's.

Okay...not to select sweaters (pick knits ), Phil, but the pre-1987 headlight system used 3 relays, not 5. But I agree that the easiest way to go is to use the 1987-up system headlight motors.

FWIW, I rewired my 1986 SE V6 4-speed car to use the 1987-up controller, and didn't use a 1987-up harness; I just modified the existing 1986 harness that was already in the car.

I also modified the 1986 headlight motors to work with the 1987-up headlight controller. So it can, and has been, done. It was a general pain, and I had to mess with it several times before I got them to work to my (almost) satisfaction. Actually, they still are too slow for my personal taste (not as fast-acting as "real" 1987-on headlight motors).

Conclusion: I wouldn't go through all that again. It was an interesting (i.e. - frustrating ) experiment, but that's about all I can say for it.

Free advice (it's worth the price ): Get a pair of 1987-on headlight motors, and use those. They don't have to be Fiero motors -you can more easily get them from Firebird or Sunbird from salvage yard.

Yeah, my addition is pretty sloppy today....
LOL!

Phil

Ya

just do the entire conversion

Ideally you want the harness module and motors....

If you want to splice wires, You can get the module and motors from other GM cars. Sunbird with the little half door and maybe late Trans Am.

Going that rout, get as much wire from the donor as you can along with the connectors.

The new motors are all around better than the old ones. The new module is much more reliable as well. The new module may be able to work with old motors, but it's calibrated to the new ones and will always work best with them.

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11-Sept-01, The day the world as we knew it ended.

I guess I didn't state the question very well. I have an 88 and would like to know if the 84-86 motors could be modified to work with it. I want to keep the 88's control module. Couldn't I just remove the contact points and the thermal overload protector on the older motors?

Another case of people responding before even reading the post. I understood it when I first read it.

The early motors dont use an overload to stop. They use an HTS. High torque switch. When the run and reach the end it torques this spring thing that turns off the motor by opening a switch. They would probably wirn in very easy. Just get the up and down signals right. You can find the colors on my site. I personally would fix the later ones. They are much better and easy to fix. But if I was going to do the swap I would use the right harness. It just plugs in. Could swap everything in under an hour.

What's wrong with your HL motors? The common problem (run on when up or down) can be easily and cheaply fixed by ordering the delrin bushings from Rodney Dickman. Something like $10 for both HL motors.

StuGood--It's not knit picking. It's nit picking. Nits are the little fuzz balls on sweaters. You aren't picking out a sweater, but picking the little balls off of it. Not flaming, just educating.

What I said still stands.... you can get the motors from other GM cars. In some cases you may have to cross them... left donor to right on Fiero etc.

What make you think you even need new motors. these are rather easy and cheap to fix most of the time. Most people just need the $10 dowel kit from Rodney and some cleaning and fresh lube.

quote Originally posted by Monkeyman: StuGood--It's not knit picking. It's nit picking.

FWIW, yes, I know. It's called a pun. I bet you just educated somebody, though . Take Care!

I just bought this car last week. The last owner changed the motors to the 86-86 style. I don't have the original motors to rebuild.

You mean 1987-on headlight motors can't be found in all of "Swope City?" Okay, since you're so persistent...

Is there just a two-terminal connector at each headlight location, like the 1987-on harness would have? I'm assuming that's the case, and that the (early style) motors that came with your car weren't even plugged in to anything.

To convert the motors you have, you want those (old style) motors, with their 3 terminals (each) to just act like plain old 2-terminal DC motors, like the 1987-on controller works with.

Here's the scoop: If you connect the white & gray terminals of a motor together, they connect to one brush. The green wire connects to the other brush.

"Many details omitted... have fun and Good Luck "

[This message has been edited by StuGood (edited 07-14-2002).]

StuGood, I must admit that I havn't heard the term "Swope City" before. Most of us call it Swoperdale . I think I have a pretty good handle on how to convert the older motors to work on the newer cars. I just have to pull them off the car and dig out the soldering iron. Anyone know which pair of wires is up and down on the newer system?

Nope. Nobody knows. Sorry.

If you find a green wire and a grey wire (at each headlight location - that is, on each side) in the car's harness - assuming it's the original 1988 harness, those are the two wires that are supposed to connect to the headlight motors.

The HL control module reverses polarity to those wires, to provide up & down. I forget which way brings the HL's "up" and which way brings them "down." Just tape the wires together temporarily, so you can reverse them if necessary. Experiment and find out...

The Michigan Fiero Club has lots of useful Fiero headlight information; read, and learn: http://www.michiganfieroclub.org/headlight.htm

"No more questions, please, ladies and gentlemen of Swoperdale- thank you and good night. And good luck with your projects !"

By the way I switch my whole 86 system to the newer one. Motors and controller. It was easy. Anyway I got rid of my old motors because the newer ones go faster and make a HELL of a lot less noise than the old style. I was so sick of that "rararararar". I am much happier with the newer style setup.

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Member MN Fieros Forever 1986 GT self installed SC3800/getrag almost everything performance wise is modified/upgraded, inside and out.

edit

[This message has been edited by Fiero Hoosier (edited 07-16-2002).]

I got it solved. Not as hard as I thought it was going to be. This is what the 84-86 motor wiring looks like.

Just tie the Blue and Grey wires together and remove the thermal overload, like this...

I will have to test in the car to find out which side is up and down but this seems to work OK on the bench.

Let me say this again. The car is an 88. The last owner put the old style motors in it. I don't have/can't find the newer style motors to swap out. I did this out of necessity, not to try to improve the 87-88 system. As far as I know all the "old style" motors use the same wire colors. Your results may vary.