C2 Headlight Assembly
The C2 Corvette (63-67) is the first year Corvette had rollover headlights. All you have to do is ask anyone what is the most difficult part of restoring a C2, and the answer is always the headlights. The problem is that the only real information out there is a single exploded diagram from the GM service manual showing one side of the headlights. Even the manufacturer of reproduction components (Melrose T-Tops) uses the GM diagram as the instructions. Internet information is spotty at best, the forums help some, but there just is not much info out there.
We set out to take the mystery out of the headlight installation and learned quite a bit along the way. It really is not as difficult as it seems. Follow the procedures that we have come up with and you can have the entire job done in a few hours. We started over from scratch. The ’67 roadster that we are working with had no headlights at all, the buckets were long gone. Melrose T-Tops came to the rescue and sent us a complete set of headlights with everything we needed. This is a surefire way to get all the parts and know they will fit together. Whether you buy your parts from Corvette Central, Ecklers, or one of the other Corvette specialty catalogs, the parts are coming from Melrose.
We wanted to update the function while we were at it. It may seem like a lot to bite off, but that is how we do it around here. The original motors were controlled by a separate switch, just like power windows, that is mounted under the dash to the left of the steering column. This opens and closes the headlights. Our car was missing the switch and because we were updating the car, we updated the controls too. Using the original headlamp warning lamp switches (located on the motor mechanism) as limit switches, the headlights now open and close when the headlight switch is operated. All you need is a standard relay and some wire. If you are doing the auto-rollover, you need to drill the second mounting pad to accept the switch. We didn’t realize this when we started, so we had to drill it in the car. Oops. That said, this also shows that you can do this part of the job with the headlights in the car for those with working headlights.
Here is the theory behind the auto-open/close: using a standard Bosch relay, the system is wired to send power to the motors via the limit switches. We ran a separate wire connected to the hi/lo switch inside the car (the wire that sends power to the headlights themselves, the top terminal on the floor switch) to the relay (terminal 86). This is the trigger for the system. The relay triggers off the headlight switch, sending power to the open circuit (terminal 87). The motor is powered until the Y-stop hits the switch, which breaks the circuit. When the headlight switch is turned off, the relay opens, sending power to the 87a terminal. This sends power to the close circuit, closing the headlamp buckets until the stops hits the closed switch, killing the power. Terminal 30 is connected directly to the positive of the battery, terminal 85 is connected to ground. It sounds complicated, it looks complicated, but it works great. For reference, the factory color codes for the headlamp motors are: Yellow= Open; Dark Green= Close.
To get better lighting performance, we also upgraded the headlamps from sealed beams to H4 halogen bulbs. The H4 bulbs are brighter and provide a longer, wider beam for better nighttime visibility. The caveat is that you need to upgrade the wiring in order to handle the added current draw. For that, we went to Painless Performance for an H4 upgrade harness. This kit comes with a universal pre-wired harness with relays and terminals ready for installation.
There are a few tips and tricks for this task. The first tip is to remove the hood, front bumpers, and grill. This will give you much better access to the interior of the nose. You can do this job without removing the bumpers and grill, but it makes reaching in easier if you do. On a lesser note, you may want to remove the radiator and AC condenser (if equipped). Again, you can do the job with it in place, but you will have more room to work with those items removed. The other tip, and this is critical for adjusting the bucket open and close position, is to work with the motors removed. While the motors can be manually moved with the thumbwheel on the inner side of the motor, you simply do not need to have the motors installed to adjust the headlight buckets.
Following the procedures outlined here, you should be able to completely disassemble and reassemble the pair of headlights in the car, including the proper alignment, in just a few hours. For more on this project, you can watch a 2-part video of the process. C2 headlight video 1 C2 headlight video 2
1. The first step in the process is bench assembly. The parts are labeled with part numbers that you can use to set out the parts on the bench in order. The pivot shafts install from the inside out and are secured by machine screws.
2. This is the layout of the pivot assembly: washer, rubber seal, felt disc, bearing, and then pivot mount. Both sides are the same.
3. The locking collar uses an Allen-head set screw to lock the bucket in place. This is the outer pivot. The pivot mount (also referred to as the bearing housing) along with the lock collar must be removed before installation in the car.
4. The inner pivot assembly is locked down with the Y-stop. The stops are what set the left-to-right positioning of the buckets in the nose of the car. The Y-stops also set the open and close position.
5. The factory switches are used to turn on the little lamp in the dashboard alerting you that your headlights are on when the doors are closed. We are repurposing them, converting them to limit switches. These are normally closed switches, which means that when the switch is not pressed, a connection is made. We are going to wire them so that when the door opens or closes, the switch kills the power to the motor. It is really simple in theory, but it can get complicated in application. No worries, we have it detailed for you.
6. Inside the bucket, the headlight housing mounts attach to several pads on the inside. These are pretty hard to get wrong.
7. The small pad is where the adjuster spring goes. The spring mounts in tandem with the plastic pad.
8. Inserting the buckets in the car is tricky. If you don’t have the grill out, this is much more difficult. Slide the outer bearing under the nose, then the inner and then slide the pivots into place. There is not much room to work with here. If your car has shiny paint, you can use masking tape to protect it.
9. The outer pivot mounts then slide over the pivots and bolt to the car with 3 bolts.
10. You have to rotate the bucket to align each bolt with the access hole in the pivot. This job takes two people, one to hold the bucket and one to tighten the bolt. This is one of the tougher jobs. It isn’t hard, but it takes some time lining up the holes.
11. This is inside the nose of the car, showing the center pivot. The Y-stop has two bolts that stop the bucket from moving once it contacts the pads that hold the switches. These are 1/4-28 fine thread bolts. Sometimes you can fit the lock nuts, sometimes you can’t. When you can, you will want to add some low-grade thread sealant to keep them from moving.
12. The buckets should be fully upright, with a slight upward angle when fully opened.
13. And flush with the body when fully closed.
14. We used our new 14.4-volt cordless drill from Ingersol Rand to drill out the mounting pad for the second limit switch. We had the radiator out, but you might get away with just leaning it back.
15. Next, we marked and drilled the pivot for the screws that hold the switch in place. DO NOT over torque the screws; the switch body is not very strong. We broke one of the switches and had to order a new one.
16. Next, we mounted the motor to the assembly. Don’t forget the catch pin on the locator bar.
17. The motor is secured to the car with a metal bar that bolts to the nose support beam. The bolt that holds this in place is really thin. Ours broke, and we had to drill it out. Be careful.
18. For the wiring of the motors, we used a Bosch style relay and some wire.
19. Two pairs (one for open, one for close) of wires need to be coupled together. These will feed the motors. This terminal will run to the limit switch, then to each motor. You can wire the system with one set of switches (one switch will feed both motors) or each motor separate with separate switches. We used 4 limit switches, so that the headlamps operate independently.
20. A standard Bosch relay has 5 terminals. 86 and 85 are the trigger sides; we used 86 for power and 85 for ground. Terminals 87 & 87a are the functions. 87 is normally open, no juice, 87a is normally closed, has juice. When the relay is actuated, they switch; 87 gets power, 87a loses it. For this operation, 87 feeds the open side, 87a feeds the close side. Terminal 30 connects to the battery positive. We ran a separate wire from the hi-lo switch (the main feed wire coming from the headlight switch that is powered regardless of the hi-low beam switch) to serve as the trigger for the relay. If you used one of the headlight wires as the trigger, the system would only work in either hi or low beam. See associated picture for the relay diagram.
21. Here is the wiring going together for the motors. The relay triggers off the headlight switch, sending power to the open circuit. The motor is powered until the Y-stops hits the switch, which breaks the circuit. When the headlight switch is turned off, the relay opens, which sends power to the 87a terminal. This sends power to the closed circuit, closing the headlamp buckets until the stops hit the closed switch, killing the power. See the associated diagram below for the complete wiring diagram.
21A. The relay triggers off the headlight switch, sending power to the open circuit. The motor is powered until the Y-stops hits the switch, which breaks the circuit. When the headlight switch is turned off, the relay opens, which sends power to the 87a terminal. This sends power to the closed circuit, closing the headlamp buckets until the stops hit the closed switch, killing the power.
22. The wiring for the H4 headlight conversion is straight forward. The pre-terminated harness must be cut in order to run the wires through the outer pivot hole.
23. The loom and all fit right in the pivot hole, nice and easy.
24. Then the wires were matched up color for color and crimped together using butt terminals. You can solder this if you want to.
25. The relays for the Painless Performance harness were mounted to the inner fenderwell behind the nose of the car. There are two relays and a fuse holder. The harness uses one of the factory headlamp plugs for the trigger, and you need to run a wire to the battery. This part takes about 15 minutes.
26. The H4 headlamp housings (we sourced ours from Ebay), have a slightly larger diameter where the terminal extends through the bucket. We trimmed ours to fit using a die grinder.
27. With everything wired up, the trim bezels were installed using the new screws provided by Melrose T-Tops.
28. The upper mounts use the sheet metal screws; the lower mounts use the machine screws. Everything works like it is supposed to.
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Hi Jefferson,
I have a c2 Corvette that I’m going to be wiring and loved the article with the dual limit switches. In the photo of the wiring and the motor the limit switches only have one wire connected to each switch. The other side of the limit switch has no wires so i don’t see how this will work. Do you have an updated wiring diagram? Also, did you end up using two relays, one for each headlight?
Thanks Ed
Have a closer look at the diagram in 21a. Both sides of the limit switches are wired. In the photo above (21), only the motor-side wires are connected, but the wires that go to the relay are connected to the other terminal on each switch.
As for running two relays, one per side, yes, that is how we did it. You can run one relay, but you will find that one side will fully close or open before the other, so you end up with lopsided lights.