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I did a little searching and haven't found any posts like this, but maybe somebody has tried it before.
I have an 85' Vette with the old style headlight motors, and the driver side motor is an aftermarket motor replacement. Not sure when this was done, but this is how I bought it from the PO. Passenger side motor worked fine, but driver side refused to open. Problem is that the aftermarket motor wasn't made with a thermostat overload switch like the GM motors, so if the limit switch fails to disengage the motor just cooks like crazy until the plastic mounting plate melts, which allows the contacts to move out of spec and the motor doesn't work. So I tried bending the contacts back, but it only worked a few times before it overheated and melted again.
So I bought a control module for the newer style motors and soldered the green and white wires directly to the motor brushes, so the internal limit switch is bypassed and the module can be in full control. This worked great for a few tries, but now it jams the gears up at the end of the travel. When the motors try to reverse they are jammed so badly that they trip the module and shut off before even budging. I can't even get the motors to free themselves with a power supply. The only way to free them is to remove the assembly from the hood and relieve the pressure, then re-mount and try again.
My theory is that these straight cut gears for the 84-85 motors are not meant to be jammed so hard, thus the newer helical gears were designed that way in order to handle the extra force. So if I can reduce the force at which the motors are being jammed into the bump stops perhaps I can prevent them from jamming? Is there a way to adjust the current threshold on the headlight control module? I'm really trying to avoid spending $500 on the new style motors... Just seems so expensive for some shoddy motors, and that money could be used for much better things.
pdx, The older style motors seem to turn faster when used like this with a newer limit module. My car was half converted when I got it with a module added and a new style motor on the passenger side but the driver side was not. I also modified the old motor to bypass the internal limit switches as you did. My old motor spins the light quicker than the new style motor but it has not jammed up so far. If yours is jamming the gears could you slow it down with a resistor but have it still move?
As you may have figured out, the motor armature in the early headlight motor needs to slide up and down to actuate the limit switches. This sliding action takes place when the headlight door hits its stops, and the worm gear "climbs up" the larger gear, compressing the spring on the motor shaft, which opens the limit switch. Proper lubrication of the motor shaft is very important. If they're working right, they won't overheat!
The "pellets/bushings" in the late model headlight motors are there for a reason! The early headlight motors don't have these pellets. When you use the late model control module with the early motors, that will cause the early headlights to jamb against the stops with much more force, since there's nothing to "slip" in the gear train!
I cleaned and lubed the headlight motors in my '84 about 13 years ago, but have never replaced any parts, and they work fine. Probably about time to give them another lube job!
As you may have figured out, the motor armature in the early headlight motor needs to slide up and down to actuate the limit switches. This sliding action takes place when the headlight door hits its stops, and the worm gear "climbs up" the larger gear, compressing the spring on the motor shaft, which opens the limit switch. Proper lubrication of the motor shaft is very important. If they're working right, they won't overheat!
The "pellets/bushings" in the late model headlight motors are there for a reason! The early headlight motors don't have these pellets. When you use the late model control module with the early motors, that will cause the early headlights to jamb against the stops with much more force, since there's nothing to "slip" in the gear train!
I cleaned and lubed the headlight motors in my '84 about 13 years ago, but have never replaced any parts, and they work fine. Probably about time to give them another lube job!
I've never given much thought to the headlight motors on my '84.
I've never given much thought to the headlight motors on my '84.
What exactly needs to be lubed? Thanks.
Originally Posted by Hot Rod Roy
The motor armature in the early headlight motor needs to slide up and down to actuate the limit switches. This sliding action takes place when the headlight door hits its stops, and the worm gear "climbs up" the larger gear, compressing the spring on the motor shaft, which opens the limit switch. Proper lubrication of the motor shaft is very important.
You'll want to use a light weight white grease, like Lubriplate or CRC Sta-Lube on the motor shaft bearings and the gears. Don't use chassis lube! Be sure to clean the contacts in the limit switches, too!
Alright, finally getting around to making this post.
So, the short version is this: if you have an early model C4 with the old style motors, don't even bother fixing them or trying to do a weird modification. it MAY work, but if it fails even once you might be stuck driving at night without any lights. This happened to me a few times.
If you are going to repair your C4 headlights your best bet will be to actually do the full conversion to the 88-96 motors. To do this, you will need:
- Headlight control module [$96.75]
- Weatherproof connectors for module [$30]
- 88-96 motors [$433.70]
- 88-96 headlight mounting brackets [$53.09]
- Weatherpack connectors and crimping tool [$60]
Control Module
While it is possible to build your own control module by wiring relays and such yourself, you're just asking for trouble if you do this unless you weatherproof everything VERY well. The module is only $100 or so on Ebay, just get it over with and buy the real thing.
Connectors
Next you will need the weatherproof connectors to plug into the module. These are kind of special so you won't likely find them at Autozone.
Headlight motors
For the headlight motors, I strongly suggest you make absolutely certain that you only buy legit OEM AC-Delco motors, or an OEM set that has been rebuilt properly. I went ahead and bought a set from Corvette Mods because their site claimed they were 'OEM factory designed' but the reality is just... Well, I'll let the pictures tell the story a bit.
Yes, those motor shafts are supposed to be straight! Even worse is that one of the motor assemblies legit wouldn't even open because the armature would get jammed on the black painted bracket of the assembly. What a giant steaming pile of horse@#$%!!! I was pretty furious about this, considering they were charging near OEM prices, and to their credit they did issue a refund when I returned them. Still, I can't believe they tried to pass this off as being OK.
I purchased a set of OEM rebuilt motors from a seller on Ebay after this fiasco and so far they have been excellent. Everything was straight and smooth, all parts worked properly. It wasn't cheap, but it was done correctly this time.
Mounting Brackets
Purchased some used brackets off a guy on Ebay, about $25 each isn't bad so I say just suck it up and do it right. It may be possible to modify the old brackets to work, but when it's all said and done you're gonna have to do custom drilling and tapping, add some weird spacers, and probably spend enough time/materials on it that you'll easily blow through the $25 you could have spent to just buy the right part. Nuff said.
Weatherpack Connectors
The connectors on the older cars are 3-pin and the new style motors have 2-pins. You could re-pin the old 3-pin connectors to work, but with only 2 pins full you aren't really sealing the connector entirely, which sort of defeats the purpose of doing it. The best advice I can can give here is to buy the proper 2-pin weather pack connectors and buy the proper tools for crimping and pin removal. If you just splice the wires together it will be much harder to service, and if you get the polarity reversed then it will be harder to swap it back over.
Now onto the flickering candles that were my original halogens... THEY SUCK! You want HID for sure with projector housings. To do this, you will need:
Relay Harness
Ok kids, ready for another horror story from Corvette Mods? Here we go!
CM sells a complete HID kit on their site for $325 (price may have changed since I got scam- err, I mean bought them) and it was even worse than the motors! Check out these pictures:
The Morimoto harness has the weatherpack connector and anodized aluminum housing, the Corvette Mods kit has the COMPLETELY UN-INSULATED CONNECTOR?!? Who on earth thought this was OK?
I'm not just being picky mind you, I had installed the CM kit and used it for a few months, but to make a long story short the relay connector would short out every time you wash the car, get caught in the rain, or otherwise splash any amount of water in through the headlight opening. This caused the death of 3 perfectly good batteries before I figured out what was happening. The problem was even worse because it could be a latent short, so you finish your drive, park the car, turn off the lights, and walk away. Then 5mins later, or even HOURS later, the headlights would turn back on! Naturally this will drain your battery in a matter of few hours, so if it happens while you're asleep you're screwed. Eventually I caught the issue as I was touching the wiring while working on something else and noticed the lights turn on without me ever touching the interior switch. Talk about a giant POS. Of course I couldn't get a refund since it had been too long after the purchase, so I am out $325 for the kit, then another $200 in batteries that gave their lives in the process of figuring this out. And in the end I still had to go out and buy the nicer high end stuff anyway just to get what I needed in the first place.
Ballasts and Wiring + Bulbs + Projector Housings
Just buy the Morimoto ballasts, amps, and harness parts. It's mostly plug-n-play with each other and only requires slight modifications when you get to the projector housing (more on that later). This is where having purchased that crimping tool from earlier will come in handy.
You will need to make an extension for the lamp wires using two sets of the weatherpack single plug connectors and about 18in of wire to keep the amp and ballast outside of the pop up housing. The original lengths are just too short and bulky so this will be necessary if you want to send the hi/lo beam and lamp power wires through the 'pop-up pass-thru' portion of the bracket. Unfortunately I didn't get the best pictures of this, but you'll understand what I mean when you take yours apart. You will also need to extend the main power wire for the relay so that it can reach the battery terminal. Make sure you use zip-ties (or something similar) to tie off EVERYTHING so that your wires don't get sucked into the radiator fan or the accessory belt.
Here are the links to the products I had to use to make this happen:
09-12-2017, 05:00 AM
1985 C4 Headlight Conversion
