Clamshell headlights (groan, roll eyes)...

[Guest onedesertdog]

Hi everyone,

 I know everyone loves clamshell problems........

I'm needing some direction, if you would be so kind.

My clams don't close....They did at one time but quit. I was taking the lower relay apart and cleaning the points, which worked for awhile.

I replaced the lower relay and did that wiring change that was wrote about. It worked twice. So now I bought another one, and replaced the top relay. I also cleaned to bare metal the fender area, checked all the connections, and cleaned with cleaner the harness pins....

   Still won't close. If I touch a hot wire to the wire going to the motor it will close, BUT only if I disconnect the plug at the bottom relay...

Any idea's, or something I'm missing? I don't want to, but I read somewhere that a separate switch could be ran to the dash.

 

  Thanks for any idea's,

.  Buddy

[Seafoam65]

                    To diagnose your problem, you are going to have to use a test light. If you don't have one, you can buy one from

your local Auto Supply store . Your test light will have a clear plastic handle with a light bulb inside and a ground wire coming out

of the top with an alligator clip .First make sure your test light is working by grounding the alligator lead and touching the pointed ice pick like tip

of the test light to the positive post of the battery. If the test light is good the handle will light up. Next turn on the ignition switch of your car

as the visors will not close with the key in the off position. With the key on and headlight switch knob pushed in to turn off the lights, go to the two wires

routed behind the grill and in front of the radiator support that go to the motor for the headlamp visors. You will see one of them is black and one of them

is brown. Ground your test lead on your light to the negative battery post and stick the pointed end of your test light into first the black wire then the

brown wire. Once you make a hole in the insulation on each wire with your light, it is easy to probe them when you need to. The way the circuit works

is that voltage is sent through the black wire to close the visors and through the brown wire to open them. If the system is working normally, when you turn off the headlights with the key turned on, the black wire will light your light.  The brown wire will also light your light while the visors are closing and until the limiter switches on the side of the motor open up the circuit, at which time the brown wire will not light your light, but the black wire will continue to light your light. When opening the visors the

brown wire will be energized with 12 volts and the black wire will light your light as well until they are fully open, then the limiter switch will kill the circuit

and only the brown wire will light your light. If at any time when the visors are fully closed or fully open that both wires light your light, that means that

the limiter switches on the outside of the motor are either bad or out of adjustment, and the motor is trying to run all the time, which will burn out the

motor pretty quickly. You say that the visors won't close, so check for voltage with your test light on the black wire with key on and lights off. If the black wire is hot and the motor won't close the visors, and the motor case is grounded then the motor is bad. If the black wire is dead you need to check the auxiliary relay and

see if the black with orange stripe wire is hot with the key on, and see if the other black wire at that relay that is not the one going to the motor is hot.

If the other black wire is hot but the one going to the motor from the auxiliary relay is dead and the black/orange wire is hot, then the auxiliary relay is bad. If neither black wire is hot at the auxiliary relay, go to the main relay and check for power at the red wire. If the red wire is hot but the black wire coming out of the main relay is dead and the light blue wire at the main relay is dead, then you have a bad main relay.The way the main relay works is

that when the blue wire is hot from turning on the headlights, the relay feeds power to the brown wire. When the blue wire is dead because the lights

are turned off then the main relay feeds power to the black wire. Do these checks and get back to me.......keep in mind both relays have to be firmly

grounded to the inner fender in order to operate. They get their ground through the case of the relay.Report your findings on these tests  and I will help you diagnose the problem. Keep in mind you can check the grounds on the headlight motor

case and the two relays by hooking your test light to the positive battery post and touching the tip of the test light to the

motor and relay cases. If they light your light the grounds on them are good. Do not try to rig something to work, it is easy

to diagnose and fix the problem you have. One other additional thought, before doing the other tests, unplug the motor

and check to see if the black wire is hot and brown wire dead when headlights are off and the brown wire is hot and black wire dead with headlights turned on. If this test fails, stop right there and report to me what you found.

 

 

Edited May 10, 2017 by Seafoam65 (see edit history)

[1965rivgs]

Buddy,

  Dont know what you did as far as wiring changes and I didnt read Winston`s post but in stock configuration the key must be in the "on" position for the motor to close the clams.

  Tom Mooney

[Seafoam65]

12 hours ago, 1965rivgs said:

Buddy,

  Dont know what you did as far as wiring changes and I didnt read Winston`s post but in stock configuration the key must be in the "on" position for the motor to close the clams.

  Tom Mooney

              Tom he is referring to my modification to the wiring so that a main relay can be used as an auxiliary relay so the that both relays are the same part number. It simply involves removing the black/orange wire from the auxiliary relay plug and plugging it into the main relay type relay at the prong

off by itself, then plugging the three prong plug into the other end  of the relay with the black/orange wire missing. with this 5 minute mod you only need to stock one part number of relay, which you can still get from GM.