high beams work, low beams won't... what gives???

dingus

Active member
Re: RE: Re: RE: Jeep clutches.

hey, subject says it all...

fuses and wiring seem all ok, headlight switch pulled all the way out (low beams) and only the parking lights turn on. if i hit the high beams, then the lights turn on (not sure if they're actually the high beams or low beams...)

any suggestions? i checked the wiring diagrams and dont see anything too obvious...

-nate
 

did you check to see if the headlights are just burned out?
 

RE: high beams work, low beams won

Are all you grounds looking good?

After that, bypass the switch like graewilf said.
 
ok well i replaced the headlight switch to no avail...

i took a test light out and tested the plug at the bulb... (3 wire plug) one appears to be a ground, the other two seem to be power.... but i'm not positive.

my question now: is this sealed beam light a dual-filament system? or, is it just one, and the high beam switch simply ADDS power to the low beam switch? is there a way i can rig up a wire to make this work? i have FSM's and chiltons' manuals available to help me out with this but i'm stuck for now... should i be looking at any relays or anything like that? i tried following the wires in search of a ground but couldn't find it. if the problem were a ground, i have a feeling that the light wouldn't work altogether...

thanks,
-nate
 
RE: Engine operating temperature for an 4.0 L

unless you have 4 headlights (which you don't) it is a dual filament. High beams are not only brighter, they are aimed slightly higher as well (hence the term high beam) have you verified power to both filaments with the meter?
 

only one of the three wires at the bulb gets power.
 
RE: high beams work, low beams won

I dont have the schematic handy, but some systems have a common hot wire (always hot) and the ground is the switched leg. Check the other 2 wires for ground/no ground as you operate the light switch. If it isn't a switched ground, then you have a wiring/switch/fuse issue.

OK, you just bought this right? I assume the problem existed when you bought it. Have you verified the wiring diagram against the headlight switch? Someone could have been in there before and swapped a wire.
 
RE: FOR SALE : MINT : (4)Brand New 15x10 Cragar Soft 8s

yes i did just buy it, however the headlights worked fine when i first picked it up. well, one low beam was out so i replaced both with some nice halogens from pep boys (like 13 bucks a side). they worked fine as well until the low beams stopped working on both.

now that you mention it, i did get 2 wires to operate as a ground when i had the test light on it. not sure if that gives you anything but its certainly food for thought.
 

Did you use a volt meter? test lights are not the best way to troubleshoot this. use an ohm meter. that will tell you if it is a true ground or if you are grounding through another bulb or such.
 
exactly, actually did that tonight and figured it out. Traced the power wire back to the first connector in the wiring harness, wire corroded and broken off pin in connector. fixed temporarily by bypassing the connector until i get to the yard saturday and cut out part of another harness to solder in. not too bad (at least i didn't find myself replacing the switch in the column or something horrendous like that!
 
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