headlight limiting switch C-2

[Ray G.]

Hello, rewireing the front lamp harness on my 65. There are two little switches used for the headlight warning light (I think). The ones one the car were pretty much blown away. On one side of the new switch the word "common" is etched, would this be for the ground wire of the harness? Thanks, Ray

[Harry Sadlock]

Re: headlight limiting switch C-2

Over the years they may have been replaced, but there are 2 very unique connectors (blue in color as I recall) on each end of harness by each switch. One connects to the upper connector on the switch and the other to the lower.

[Ray G.]

Re: headlight limiting switch C-2

Yes Harry thats correct, the problem is the switch will fit either way, so you don't know which wire spade should go where. Thanks, Ray

[Harry Sadlock]

Re: headlight limiting switch C-2

Ah yes, my old harness looked like a cut and paste project. As I remember the new harness had different length wires for the switch, I assumed the shorter went to the upper and the longer to the lower. It's been working fine since the install.

[Mike Yager]

Re: headlight limiting switch C-2

That was the conclusion I came to as well since the one wire really did not seem long enough to reach the other terminal. Just to be sure I double checked the wires before I hooked them to the switch by using a continuity tester. You should be able to easily trace the wires for the switch back to the firewall connector. I then unplugged the firewall harness and put a continuity circuit tester on the section that goes from the firewall harness to the switch. If you have long enough test leads, you can work the switch and determine the correct connections by checking the continuity.

[John M.]

Re: headlight limiting switch C-2

Ray... I believe you have a Unimax switch , GM 3821864 Group 2.755 marked common on one end and norm closed on the other. Norm open probably also appears below norm closed but there is no spade connector at the norm open position on the GM switch . They do manufacture a switch in the same body with three spade connections in which case you need to know which spade is common to the other two.

Current should flow through the switch until the headlights reach the full open position, then the stop depresses the switch plunger and the circuit should open. I agree with others that harness length will dictate which wire reaches which spade but you can't wire it backwards.

I believe the ground wire, at least in 67, attached to the case of the headlight motor itself and you have to use a proper length screw so as not to damage the motor.