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1963 Chevrolet Corvette Z06 - Resto Clinic

'53-'67 Corvette Tech

Jeff Bernhardt Nov 1, 2007

Headlight Rotation No. 1
I have a '67 convertible with a 327. I have always had problems with the headlights. They don't rotate easily, and usually have to be "helped" by rotating the knob on the back of the motor. I have replaced the motors and installed a gear kit. I still have these problems. I can't tell if the motors don't have the power to rotate the headlight assembly around or if there is binding in the assembly. I do know that the electrical connections are all good, and that the motors are getting power. Is this a common problem?
Brian White, Via e-mail

Headlight Rotation No. 2
I would like your advice on "fixing" a lazy headlight on my '66 Corvette. When I activate the switch for down or up of the headlights, I have the driver-side headlight rotate at a much slower pace than the passenger side. Is it a problem with the motor or something else?
William H. Hahn, Via e-mail

Let's separate the rotating headlight system into three categories, each of which can cause the problems that are experienced in the real world, especially in cars of this age. The first category would be the headlight housing-the rotating assembly that mounts to the front of the car. Two shafts from the housing pass through two spherical bearings that are held by two bearing cups that are mounted to the car with three bolts each-in a nutshell. The housing is held center in the opening of the front of the car by a pair of "stops" on the shafts: one ring-shaped on the outboard shaft, and the other "Y" shaped on the inboard or driven shaft. To check the ease of rotation of the housing, the motor must be disconnected from the assembly. Pull the hairpin clip from the stub shaft of the inner bearing housing, and remove the small bolt from the mounting plate of the motor. Lay the motor aside and check to see if the headlight housing has any drag to it. You should be able to watch the housing complete a full cycle from open to closed or vice versa after simply starting the rotational effort with your finger. Yes, it should rotate that easily. If not, locate whatever is binding and make a repair. Chances are you'll find bodywork, corrosion, improper hardware, improper mounting procedures, or the sheer genius of some prior shade tree atta-boy that had a hand in it. If necessary, take the assemblies out and fully disassemble them. Clean and inspect the parts, and repair or replace as necessary. Don't forget to lubricate the shafts where they pass through the spherical balls, and pack a little extra grease in the cup to help keep moisture out. When they rotate easily with the one-finger test, you're ready to move on.

The second category is the headlight motor. Remove the headlight motor from its wiring and take it to the bench for testing. With a good 12V battery at hand, make two 10-gauge jumper wires from the battery posts to test the operation of the motors. Use a female terminal on the end of the positive wire to connect to one of the male spades inside the ivory-colored plug of the motor. After you've made the positive connection, make the negative connection by holding the negative wire to the housing of the motor. You should see the small wheel of the motor spin freely, and without pause or interruption. Pull the negative wire from the housing and connect the positive wire to the other terminal within the ivory plug. Reconnect the negative wire, and you should see the wheel spin once again, only in the opposite direction-again, without pause or interruption. Both motors should spin freely, evenly, and at the same speed. If not, look for problems within the motor. The most likely problem is the aluminum drive gear that is turned by the screw on the end of the motor armature. I guess this would make it the driven gear, except that it drives the headlight housing. Look for worn, distorted, or flattened teeth on this aluminum gear. Replacements are readily available from all of the Corvette parts vendors. Look out for the cheapie aluminum gears that are still circulating out there. They won't fit the shaft of the headlight housing, which renders them absolutely useless. Be sure to pack some grease in the gearbox of the motor.

The third and final category of your headlight system is the factory wiring. Electric motors call for the highest amount of current in your car's electrical system, whether it's a starter motor, blower motor, or headlight motor. After 40 years of service, moisture causes corrosion within the electrical connections, which reduces the amount of current flow through these connections, which causes overheating of the wiring that not only further reduces the amount of current flow (increased resistance), but also melts the plastic connectors and makes them dang hard to take apart. Plus, it makes the motors work slowly. Look hard at the two female wiring connectors within the green plastic plugs on the ends of the factory wiring harness. This is the business end of the harness, and the source of a lot of wiring maladies. If you spot any green corrosion on the copper or feel brittle wiring up to the plug, plan on taking these spades out of the plug and replacing them. Without adequate current flow to the headlight motors, they are not going to work well. The final place to look would be at the headlight motor switch. This switch toggles heavy amperage that can burn the contacts within the switch, rendering it inoperable. On its way out, it will still work, but not well. Take it apart and lightly sand the contacts with 400-grit sandpaper or replace it with a reproduction.

Tag, you're it
Some years ago I did a frame-off restoration of a '61. One piece that was missing was the VIN plate that was originally riveted to the steering column. Since I did the frame-off, I verified that the frame numbers matched the numbers on the title. Do you know of anyone who reproduces the steering column plates, and is it legal to do so for a car that has a title that matches the frame number?
Ed Schadle, Via e-mail

The first step is to check with your local authorities on the legality of a replacement vehicle identification number in your state. Some state authorities, after a theft check, will issue their own VIN tag to your car. Unfortunately, it can be of an entirely different number, which will negate the title and any other original identification numbers to your car. A rider may be attached to your title, or a completely new title may be made at this point. I have seen Corvettes that have bizarre number plates in place of their original VIN tags. This, obviously, may have a negative effect on the value of the car.

I did a web search and read through about 30 pages of results, coming up with little on replacement VIN tags. One site showed a little promise, although this guy seems to be a Ford man (don't trash him for this until he helps you) at The company name is A.G.Backeast, with a byline of Tag Restoration Since 1982. I don't know anything about this company, but it's a path. The only other thing to do is to get with other Corvette owners through N.C.R.S. forum blogs, club events, and so on. See if anyone else has had experience with this problem, as I'm sure you're not the only one. Good luck.

Information delete
I have a '66 coupe. The radio is aftermarket and the antenna is on the wrong side. I was told the car was a radio-delete car, and someone installed the radio and antenna. Is there any way to research the car and confirm the radio-delete issue? I would like to delete the radio, or purchase the correct one and move the antenna or delete it also. Any info would be appreciated.
Dave Eastwood, Via e-mail

You don't have a buildsheet on the tank of your '66, but you can do a little sleuthing and possibly pick up some clues as to whether or not your car was a factory radio-delete car. If a previous owner added the radio and antenna like you stated, it's not likely that he added all the components the factory would have on a U69 radio car, especially if he didn't adhere to strict factory standards inasmuch as installing an aftermarket radio and mounting the antenna on the wrong side. If your car was originally a radio-delete car, there would be no power antenna switch mounted to the left console cover by the side of the radio.

Do a quick check under the hood. All Corvette engines used the zinc-plated spark plug boot heat shields, but only radio-equipped cars had ignition shielding with the lower J-shaped shields along the sides of the block, horizontal spark plug shields, and a distributor cover with vertical shields at each side. Are there capacitors mounted to the coil, voltage regulator, and blower motor? These were only used on radio-equipped cars. Capacitors were also plugged into wiring under the dash if your car came with a radio, at the brake light switch, turn signal flasher, ammeter plug, and the common brown accessory wire via a loose connector near the ignition switch.

Look above the left muffler (if it's an under-car exhaust system) for a repaired hole in the upper quarter-panel where the original antenna might have originally been located. With a light and a scotch brite pad, you should be able to do a thorough inspection of the bare fiberglass. Look for a power antenna mounting bracket mounted to the splash shield (a vertical fiberglass panel bonded to the quarter-panel just behind the rear wheel) with a two-hole nut plate on the wheel side of it. These would only be present on a radio car. A ground strap-a long, thin strip of copper-passes over the number four body mount bracket near the antenna mount and screws to the frame with a bolt and star washer, if it's a radio car. Woven-copper ground straps would be located at the accelerator lever, connecting it to the rear intake manifold bolt that mounts the spark plug wire support, the right-hand motor mount, the birdcage to the frame at the left No. 1 body mount, and the exhaust clamps to the frame crossmember (for under car exhaust systems). If all these things are in place, it's likely you have an original U69 radio-equipped Corvette. Either that or a previous owner did a superior job with nine-tenths of the installation, and then screwed up the antenna install.

Restoration Questions?
Resto Clinic
9036 Brittany Way
Tampa, FL 33619
While mail cannot be answered personally, letters and responses will be published as space permits.



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