Headlights are extremely messed up

My harness for my headlights was extremely corroded and gunked up, so I bought a new harness. Spliced the wires and ended up with one dim headlight, one bright. When switched to high beams they’d just reversed. I tested all wires and changed every one I could. And ended up just wiring it to be bright at all times. No low beams. No, I’m not blinding people because my headlights are too dim for me to even see with them hardly. That’s another question. I have looked and I can’t really find any reason as to why they are so dim. I’ve replaced bulbs several times and nothing makes them brighter.

 

Bad grounds can cause dim headlights.

 

You got a good ground?

 

Not too sure, where are the headlights grounded?

 

How many wires on each headlight? If it’s 3 wires one is power for low..1 for high ...the other is ground...I wouldn’t sleep till it’s fixed

 

The white with a black strip is the ground wire.

 

If you bought an aftermarket harness
Be sure the wires are pinned correctly to the harness.
You need to use the diagram above to reference the correct color wires to the pins.
Both Plugs (H2 and H1) use the same pin out.

Harness Pin Out


Hint* #3 pin on both connectors should be Ground (White-Black)
@Jimmyh , correct me if I’m wrong?

 

^Yes, that's the correct connector for the headlights. Yes, terminal 3 is ground, and as shown in Jimmy's schematic, terminal 1 is low beam and terminal 2 is high beam. The "brown" in the pic above only refers to the color of the plastic housing.

 

Thanks Man.
You and Jimmy are slowly teaching me to read wiring diagrams. LOL
I always feel better when one of you help me out with electrical questions here.

 

Was a little confused because the harness that I was given had a red black and green. Whereas the headlights are white and black, red and white, and red and black.

 

Regardless of the colors, with the connector information along with the schematic and a digital multimeter you should be able to figure out what is what by turning on the lights and reading the wire voltages as you shift between high beams and low beams.

Keep us posted and good luck.

 

You could also use a multimeter to check for resistance between the ground pin on the plug and a known good ground on the truck.. if there’s a lot of resistance or it’s open/out of limits you have a ground problem

 

Will check that when I get home, I appreciate it, will update when I check