Dim headlight, need info on rewiring.

[IHI-RHC7]

Hey guys,
I've tried searching, but to no avail. The drivers side headlight on our 91 is stupidly dim, whereas the passenger side is nice and bright. Flipping on the brights makes no difference and I've already swapped out bulbs.

I remember talking to Shawndude long ago about how he rewired his lights to correct the problem. I have full power at the left headlight fuse, so the problem must be somewhere downstream from there. Any help on this would be greatly appreciated.

Thanks,
-Jake

 

[Nick M]

Do a voltage drop test. You have high resistance on either the power or ground side.

edit: I guess I shouldn't assume anything. Voltage drop is having the leads on the same wire, not doing a potential between two wires.

Put one at the power source, the other at the light. Then switch to the other side of the light and ground.

 

[Big Wang Bandit]

Was the same way on my old 87, It was a fuse underhood.


Im not sure. :/

 

[jetjock]

The loss of 1 volt robs the typical halogen lamp of nearly 27% of it's rated lumen output. This loss is typical in most cars even with new wiring. To overcome it use new relays located at the lights, use the stock circuit to drive those relays, and wire #10 fused feeds to the battery or an aux buss taken off it or the alternator. Run a new common ground too. You'll be surprised at the difference. Buy decent lighting if you want better. Dan Stern is who I get my lenses from: http://tinyurl.com/29lgzq

Or stick with stock and do Nick suggested. Drop testing is the best method of finding resistance in loaded circuits.