Lights are dim on the left not right

I just got my jeep back from having a new harnes installed. For some reason the headlight and tailights are 50% less bright on the left side then the right. Any ideas of what can cause this from a wiring perspective. The guy who did it lives far away and I would rather fix it myself then have to go back that far to him. Thx.

 

Disconnect the battery first, before you do anything.

Check and recheck all the wiring connections, especially the ground connections. Then check 'em again. Even if the harness is new, make sure all the connection points are clean too, no rusty nuts, screws, washers, etc. Replace any nasty hardware, wire brush or sand away rust or corrosion to bare metal. Make sure all the crimped-on terminals are crimped tight enough (loose crimps make nice little mystery problems), and if you brush a little grease on all connections it helps prevent corrosion.

 

I agree with Ron. I'd be willing to bet it is a bad ground connection on that side.

 

I will vote for loose ground wire also. Iltes on my trailer fade on one side. pull the lite and cleaned the ground, now they work fine.

 

I vote ground also.
Mine had me stumped for awhile.

 

he could have the high/low beam wires crossed on the headlights
on the tail lamps, he could have crossed the wires there also
turn/brake wire (brighter) vs the parking lamp wire(dimmer)
or...
bad ground as mentioned above
only 3 possibilities that I can see

 

Thx guys, it was a bad ground. Now I just need to find the device thats pulling my battery down overnight.

 

An aid in tracking down the draining circuit is to use a test light. Disconnect the negative battery cable at the battery and connect a test light in series such that one end of the test light is connected to the negative battery post while the other end is connected to the negative cable you just removed from the battery post. If you have a battery drain the test light will light up.

If the test light is lit, pull a fuse from the fuse panel. If the light goes out you found the circuit that is causing the drain. If the light does not go out, replace that fuse and move on to the next one until the draining circuit is found.

Once the draining circuit is identified you can trouble-shoot that particular circuit until the problem is fixed.

Good luck.

 

I didn't know you could do that. Great advice!

 

Excellent advice!!!! Very simple method.