One dim headlight

Hello,

I know this topic has received some attention before, but I am stuck on it and am hoping for some opinions on what I am missing.

This is for a 2000 Dodge Ram 1500 with single headlights. Recently, the driver’s side headlight is dim on both low and high beam settings.

I’ve checked the headlight fuses in the PDC. Both the left and right headlight fuses are good (e.g., show continuity, with less than 1 Ohm of resistivity), and both have +14 VDC across both sides.

If I pull the left (driver’s side) headlight fuse, nothing changes. If I pull the right side fuse, both lamps go out. So, both sides are being powered through the right side circuit. I’ve seen other threads that suggest this is due to a poor ground on the dim side.

The headlight plugs look very clean, inside and out. I did find two ground leads on a stud near the dim headlight that were corroded, and cleaned/replaced them, to no effect.

Given that this is a switched-ground system, can I splice the ground lead from the right side headlamp to the left side lamp? Or should I be looking for something else? Like another ground lead? I’m not sure where to look.

Full disclosure: this truck does have a Western snow plow kit on it. I don't think that the problem is related to the plow kit, though, because the problem is recent and the plow kit was installed years ago. And, when the plow is attached, its left headlight is also dim.

Any hints would be appreciated!

Thanks –
PMN

Tag for answer. I've got the same issue

Why don't you run a temp ground from the dim headlight to the battery negative post just to make sure its the ground. Also what your voltage at the headlight with it plugged in to the headlight and on? Does it stay at 14 volts?

Your truck should have 9004 headlamp bulbs. The Sport headlights have 2 bulbs in each side - 9007 low beam outers and 9004 hi beam inners. While they use the same style connector plug, they DO NOT wire the same. Putting a 9007 bulb in one side in place of the correct 9004 can cause problems like you describe.

I know this post is very dead, but since I fixed my same issue not too long ago I figured I'll throw my hat into the ring. My issue was a nicked wire in the headlight harness that had corroded, this caused a short in the headlight harness and caused my drivers side headlight to be so dim it was like the headlight was off. Fix was to cut and splice the wire back together, however you will have to dig into the wiring mess that next to the drivers headlight. However, if you look at your dash and the high beam indicator never goes off when the headlights are on, then you have the issue that EvilSpirit mentioned.