Re: dome light repairs

Posted by HH56 On 2014/1/7 13:43:27

Brian posted essentially the same thing as this long winded explanation since I let the forum time out on me before it was posted. In addition to his cigar lighter questions, I have a couple of things worth checking so will go ahead and post my response.

The interior lights and the trunk light are all powered off the same fuse but via different paths. Since the fuse only blows when a bulb is inserted, chances are that portion and loom is OK. Because the fuse only blows when bulbs are inserted, something to check would be the sockets themselves. Inserting a bulb pushes the contact plate rearward against a spring & moves the wires. If the insulation has shrunk back or deteriorated, the act of inserting a bulb could move the contact plate enough that a wire could touch against the shell & short. A non functioning trunk light could well be the built in tilt switch -- it easily corrodes and is a frequent source of no trunk light.

As far as function, turning the headlight switch knob provides a ground to the rear lights and also one to the front center courtesy light. It should illuminate with the rear. That portion of the headlight switch is also in parallel with the 2 door switches so that either door would also light the front and rear interior lights. All that is done via a short aux wire harness off the headlight switch.

The 55 and early 56 had two door switches for two circuits. Later 56 cars use a single double contact door switch to provide two separate grounding circuits. One portion for the interior lights and the other portion and contact for the side markers. That would be a place to look. Make sure someone has not substituted a single contact switch and tied the circuits together.

I don't know if anything was done when making an Esquire other than some molding and trim changes. If there were electrical changes then any number of possibilities might occur.