PFF - Pennock's Fiero Forum, PDA Edition

Upgrading from Gen 1 to Gen 2 headlight motors may not be that hard (Page 1/2)

Dennis LaGrua

NOV 17, 02:58 PM

While they are two different systems the motors are mechanically interchangeable (they bolt right in) but the wiring is different. You would need the motors, the 87-88 headlight module and a bit of rewiring time. I found the diagram below from an old link to the Fierolist via the Calgary Fieros website..

Wichita

NOV 17, 03:10 PM

Why not just rebuild the Gen 1 motors?

Mike in Sydney

NOV 17, 05:51 PM

quote

Originally posted by Dennis LaGrua:

While they are two different systems the motors are mechanically interchangeable (they bolt right in) but the wiring is different. You would need the motors, the 87-88 headlight module and a bit of rewiring time. I found the diagram below from an old link to the Fierolist via the Calgary Fieros website..

There's a bit of difference. You need to shorten one of the three mounting bolts holding the motors to the lift frame by 1/2" or else it will bind. Can't remember which one but it will be obvious when you test fit the motor. There's a good set of instructions in the FAQs & How to section (http://www.fiero.nl/forum/Forum9/HTML/000002.html).

I've put '87 headlight systems in both of my '86GT's. The results were great: quieter motors, faster lift, easier motor rebuild (plug & play and new replacements are available). Wiring-wise it's a straight swap for the harnesses. The only issue I had was where to mount the module. I put mine under the left headlight instead of putting it on the frame in the left front wheelwell.

BTW, taking the hood off will make the job a lot easier.

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Mike in Sydney

[This message has been edited by Mike in Sydney (edited 11-17-2020).]

fierofool

NOV 17, 06:26 PM

I converted my 86 and the hardest part was getting the harness inserted across the front. With the hood removed, there was one small bit of metal that I had to bend to make clearance for the harness to push down inside. Like Mike, I left the control module under the left headlight. It didn't take long for it to fail due to water penetrating the case.

After that, I placed the replacement module against the fender wall, marked and drilled an attachment hole while holding the module in place. I had to make several attempts because the fender wall is multi-layered in several areas. I finally found a single wall just up from the grounding wires that are present. The one nylon expander has been holding just fine for years.

Then I jacked up the front of the car, removed the wheel and loosened the front of the fender well liner, and mounted the module underneath with the nylon expander rivets. The orientation doesn't really matter, but I rotated the module 90 degrees when I was drilling the holes so that the module was mounted with the same factory orientation and wouldn't cover the factory hole where the harness passes through the fender wall. There are circuit identifiers cast into the housing where the harnesses plug in that can identify the up and down as installed at the factory.

Dennis LaGrua

NOV 17, 09:07 PM

quote

Originally posted by Wichita:

Why not just rebuild the Gen 1 motors?

That is my first choice . I have rebuilt them but if the motor or brush arms are burned then you are S.O.L. The gen 1 systems are also a complex system of switches and relays. There are many areas that can cause a problem. The gen 2's are a far simpler system and complete new aftermarket headlight motors are still available.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

RWDPLZ

NOV 18, 12:53 AM

I installed Gen 2 motors in my 84, the later harness plugs right into the C100 bulkhead connector. I converted the radiator fan motor/shroud over to the later style at the same time since my car has the 84 only 2-speed fan setup.

Dennis LaGrua

NOV 18, 03:08 PM

quote

Originally posted by RWDPLZ:

I installed Gen 2 motors in my 84, the later harness plugs right into the C100 bulkhead connector. I converted the radiator fan motor/shroud over to the later style at the same time since my car has the 84 only 2-speed fan setup.

Yes many owners use the later harness, module and motors as a plug and play solution but if you think about it the Gen 1 system already has a harness. It just needs to be rewired as per the diagram shown in this post. The later 87-88 headlight harnesses are getting scarce and are hard to find.

cvxjet

NOV 18, 06:22 PM

I did the early (85) to late (87) swap on mine...I really don't trust those earlier motors- they can run on after you have walked away and then overheat and catch fire; Had one that was run the previous day......Did not run it the next day but just TAPPED the knob on the motor and it started trying to run....was at 160 degrees by the time I had disconnected it. I also had two "Mystery" dead battery situations which I now believe was perpetrated by one of the HL motors in the middle of the night.

I also installed a >Keyed power< relay in the main power wire so that (with either system) after the key is out the motors cannot do anything...I installed mine in the front compartment but it may be better to put it on the inside of C100 under the dash. Here is my thread on that; http://www.fiero.nl/forum/Forum2/HTML/143215.html

steve308

NOV 18, 08:07 PM

FYI over in FAQ is a nice how to convert / change gen1 to gen2 write up.

ragoldsmith

DEC 18, 08:29 PM

Good information here. I've read through the FAQ, but I like seeing other discussion, too. Thanks for the info, everyone!