56 Wiring Problem

[Jerry Garrett (14448)]

I've just installed total new wiring harnesses through the car. My problem is that I don't have tail lights or license lights when headlights are on. Brake lights work and turn signal lights, so I don't suspect a ground, but I ran a by- pass ground to the harness ground feeding the rear lights where it mounts to the bumper support, but it didn't work. I have the headlight switch wiring and dimmer switch hooked up according to wiring diagram. What am I missing? Any help? Thanks for your help.

[Verle Randolph (14764)]

Re: 56 Wiring Problem

Jerry,

I don't have my wiring diagram so I am shooting from the hip.

There is one separate wire to the back that powers the tail lights and license plate lights. Your symptom suggests that wire has no power. Check for power with your volt meter to a good frame ground. If there is no power your problem is either no power at the source or the wire is open (cut). Look at the color of the wire and check for power under the dash. The problem can be the light switch. Make sure all the wire end connectors are all the way in the plastic housing.

Verle

[Mike Ernst (211)]

Re: 56 Wiring Problem

Primary potential culprits, as I see it:
dimmer switch
headlight switch
turn signal switch in steering wheel backing cup

[John Hinckley (29964)]

Re: 56 Wiring Problem

Jerry -

The taillights and license light are fed by a 20-ga. black wire, directly from the headlight switch, that doesn't pass through either the turn signal switch or the dimmer switch - just goes directly from the headlight switch. Your grounds are fine (or the brake and turn signal filaments wouldn't work), so that wire isn't getting power - check it at the switch and work your way back from there.