Originally Posted by CmptrNerd
But other than that it could only be the wire right? Maybe one is getting more power than the other? Please help, thanks!
I assume if one had a bad (e.g. oxidized) reflector, it would be kind of obvious in daylight when you compared one with the other. In fact I think one of mine is little shinier than the other in daylight, although they both light up pretty much equal at night.
I'd say you have either bad power or a bad ground to the offending light. Measure the voltage at each light and see what you get. Specifically, measure between the power and ground connection _at_ each light, and I think you'll find that one is worse than the other (in fact it pretty much _has_ to be, from what you're describing).
Now measure voltage on each between its power lead and a known-good ground, such as a wire clamped to clean metal under the hood. If the light is dim because its power lead is bad, you'll measure the same low voltage this way. If the light is dim because its ground lead is bad, you'll measure a higher voltage this way, because you've now provided a good ground path instead of a high-resistance one.