72 Charger hidden headlight problem

[Polara426]

Working on the headlights I had the motor rebuilt and it works fine when I direct power the motor it opens and closes. when I hooked it up to the light switch and ignition switch the relay doesn't seem to work it opens when I turn on the key without the lights on. Any ideas? I installed as service manual says and am using factory relay but have a aftermarket wire harness (american wire ) this is a restomod.

 

[dodge1972]

Keep in mind the light switch turns-on relay to provide power to headlite motor. When the motor reaches its limit the doors are open, it turns off and hold the position until the relay is de-energized to apply power to motor. The motor like a door panel motor reverses direction until it reaches it limit. Now the doors are closed. Motor turns off. When the power is reapplied the motor reverses direction to open the doors. Using a 12 volt meter, check the power to the motor. If the motor power is there. motor should operate. Note the direction or power is reversed the light switch is off. Again similar to door windows, the relay is reversing power to the motor. Make sure you have a ground switching or reversing. Motor operates by appling both ground and 12 volts. Thats how it changes direction. Good luck Robert

 

[Polara426]

Thanks I will check.

 

[72sunroof]

Working on the headlights I had the motor rebuilt and it works fine when I direct power the motor it opens and closes. when I hooked it up to the light switch and ignition switch the relay doesn't seem to work it opens when I turn on the key without the lights on. Any ideas? I installed as service manual says and am using factory relay but have a aftermarket wire harness (american wire ) this is a restomod.

OK do you have headlights in... Do you have LEDs? Without a resistor there is no resistance when they are off.
If the relay does not see any resistance from the headlights it will let the power through to open the light covers.
Check to see if the input has power with just the ignition on.
Hopefully you have a schematic to trace the wires going to the relay.

 

[T2R9]

Key must be on for the door to open. With the key on and headlamps on do you have 12v at the motor connector? Do you still have the factory relay? I replaced mine with a quality Bosch unit using this wiring diagram and an inline fuse to replace the factory circuit breaker.

 

[T2R9]

With the above if your using an aftermarket harness. Pin 30 is 12v keyed, 86 is from the headlamp switch, 87 and 87a are to the motor, open and close.

 

[71charger_fan]

The American Autowire harness didn't have provision for concealed headlamps. I had to add a wire from an unused accessory to the relay. Plus added a wire from the HL switch to the relay. My original relay was toast so I adapted a relay for a '65 Riviera's HL doors. There's also a small circuit breaker attached to the factory relay. Check to see if you have power into AND out of that.

1971 Charger Concealed Headlamp Motor Relay Alternative | Allpar Forums

headlight motor relay upgrade for 1970 & up (dodgecharger.com)

 

[Slap Stick]

IIRC (my pornographic memory isn't what it used to be) on my 72 the covers would drop but the lights remained on. Wiggling the HL switch would make the doors go up and down so I manually opened them until I got a new switch. Replaced the old one and all was well.

 

[Polara426]

Thanks for everyone's input I have a relay and circuit breaker on order. I will update when I get them installed.

 

[Polara426]

Got the Hidden Headlights working used aftermarket relay and circuit breaker. My original relay must have been bad.

 

[71charger_fan]

Amazing how simple that circuit is when you take a minute to trace it out and think it through.