[kvinmn]

I have an interesting problem with my 68 XR7. I replaced the side marker lights with the bulbs listed in the old Sylvania catalog.

Put the driver's side light in and it worked!

Put the passenger's side light in and the headlights dimmed, the front turn signal lights went out and so did the driver's side marker.

I pulled out the passenger bulb and it went back to normal. I decided I had a short in that assembly and left the bulb out.

Obviously, when I drove it later that evening, the headlights started flickering, the side marker light went out, the turn signal lights and the dash lights went out as well.

The next day, I pulled the driver's side marker light out and the rest of the lights went back to normal.

I don't have a shop manual yet (on order) so I don't have a wiring diagram. Is it a safe assumption to make that all of those lights are on the same circuit and that BOTH side markers have shorts?

You'll have to forgive me...I'm new...

 

[dan]

check the grounds

I would check the grounds. some times when the one head lite dims I clean the plugs and get all the green crap off try that Dan

 

[fordsnharleys]

I agree...check grounds

I recently went through a similar problem, but on a gmc truck, a rat chewed the ground wire in 2 and every time I used my turn signal when the headlights were on the headlight would flash instead of the turn signals and marker lights........just worth a shot..look at those ground wires.

what you are explaining could be due to a ground, because if electricity does not have a path to travel through the lights to ground it will go to a different part of the circuit and find whatever ground it can...it would do funky things.
Just an idea.
Justin

 

[vfret]

three for three

Yea, what Dan said. A bad ground can cause the weirdest things. Anytime I have crazy $hit going on I usually find a crappy or nonexistant ground.