Headlight problems

[roderick]

I have a 73 super the problem i am having is the right headlight burns very dim.I have checked the ground which is good.any help would be appreciated.

[The Newf]

Low in circuit voltage to the headlamp, or your good ground is bad.

[Marc]

Bad ground on that side is a likely suspect (it's the brown one in the pigtail harness coming into the trunk from the fenderwell).

Another problem, usually encountered after a fender's been changed, is that the three wires going into the plug on the back of the headlamp bulb are connected improperly - typically that puts the hi & lo filaments in series, increasing the resistance and causing a dim condition.

Looking at the bulb from the back, the wire going into the 12:00 position should be the yellow (low beam) one. The white high beam wire goes into the 3:00 (outboard on the RH side) position and the brown ground wire goes in at 9:00. The connectors each have a little tab which locks them into the 3-prong block, if they need to be rearranged it can be compressed by going into the end with a tiny screwdriver.

[helowrench]

High, low, or both?

[roderick]

yes there is just a glow on that side.

[Marc]

Another thing to do for symptom elaboration: remove the fuses for the left headlamp (both high & low beam) to see if that makes the right side "glowing" stop. If it does, that's nearly-positive confirmation that the ground is bad on the right.

An open ground could be a problem inside the bucket, even a broken lug on the lamp itself...