I noticed the other day myRH headlight was a lot dimmer than the LH what might be the issue? Also should the the running lights stay on with the headlights? I found it strange that my running lights will turn on with the first pull of the head light switch but shut off we the headlights are turned on. To make it more interestingwhen you click the highbeams on the running lights come back on.Any help is appreciated.

1966 Mustang Coupe
Brian

 

First thing to check for the headlight is the grounds. This is the problem in the majority of the cases. To verify this is a problem, you can pull the bulb then probe the connector. You should get close to the battery voltage (assuming your doing this w/o the engine running).

The parking lights are designed to go off when the headlights are on. I do not know why they would come on with the high beams. Something fishy?

 

I think you have grounding issues, check and redo all of the grounds around both headlights. I think your headlight is getting its ground through the parking light,,,,

Make sure that the connections to the car body are tight, (where the wires screw down) and not subject to corrosionetc.

 

Same prob on my '66 when I initially purchased it, pull the bucket and check the connector on the back of the bulb to insure you haven't lost your ground wire through corrosion or just broken. I believe it's the green/black wire.

 

here ya go. http://www.hammar.dyndns.org/~djhamm...wiring1966.htm. handy little webpage for your wiring.