Roger L

I took delivery a couple of weeks ago, 66 coupe, and today was going to take care of a couple minor issues. One being the right side high beam bulb is not working, I assumed it was simply the bulb. I ordered 2 new high beam bulbs and proceeded to change the bulb. Figuring I would change the 2 inner high beam bulbs so the light color was same.
The 2 low beam bulbs work fine as well as all other interior lights, parking lights, turn signals and stop lights,
When I turn on headlights both low beams are OK, when I press the High Beam switch the left side high beam comes on and the left side outer low beam goes high, so left side is working correctly. However on the right side, there is NO high beam, and the outside low beam light doesn't go high, so NO high beams on right side..
I tested the new high beam bulb and confirmed it is OK, next I put a volt meter across the inner high beam plug wires on right side and reads "0" volts, so interruption some where?
Next I removed the (2) 8 pin wire harness plugs thru firewall, cleaned up what looked like some corrosion, sprayed with CRC and put that back together. The headlights rotate OK and all other lights are working except the right side high beams.
I have exhausted my trouble shooting knowledge and need some advice. Not knowing the construction of the wires going into the headlight bucket, whether they just pass thru side and get twisted 180 degree when rotating buckets or if there is a commutator plate with contacts outside of bucket. So I have stopped and need some expert guidance to trouble shoot the electrical gremlin.
thanks for reading this, Roger

rich5962

Roger,

There's no rotating commutator. Each bucket uses a extension harness which passes through the outer shafts. It then connects to a 3 prong connector to the forward harness. Check that connector on the right side for voltage. If it's not there then it's likely open between the left and right side in the harness. The same feed wire goes to both sides from the hi beam switch.

It's hard to get access to the connectors. With the hood open make sure you put a bolt through the hood support rods to keep it solid while your arms are in there.

65GGvert

Check the connectors at the front on each side. You could have a corroded or broken wire or contact in either side on the connection for the light green wire. It splits in the left side connector and feeds to the right side. The black and the tan wires have to be making contact or you wouldn't have the dim lamp working on that side. Focus on the light green.

midyearvette

there is a small connector in front of the core support drivers side that link the headlight bulbs from one side to the other.....im' betting it is corroded...jmo....

stingrayl76

Looks like a consensus.

Roger L

Hi Guys
Looks like a consensus is 100% spot ON. I found the connector on right side where it exits the headlight bucket, opened it, cleaned connections which was difficult to say the least, sprayed with CRC and plugged back together. Everything works now. Thanks for help and a wealth of information.
Roger

John S 1961

You may wish to consider adding relays for the headlights, this will make a dramatic difference in the light output. It also relieves the high current from your (old)wire harness and (old)headlight switch. For data see Madelectrical.com