Another Low Beam question????

[1of1547]

Hey guys, last night the lights on my girlfriends 2003 KJ Limited didn't come on when she turned the switch on. I've done a search and it seems to be a problem with these. Mine is just like everyone else's, everything works but the low beam. Highs are fine along with the driving lights. I've done some testing and hope that you guys can help me. So far I've switched the high and low relays, still didn't work. I tested both relays in the high relay switch and they both are fine. Or at least it was clicking and the high beams came on. In the relay socket I tested #30 terminal (top one) that the manual says should be hot with a test light. The high beam had power, the low beam did not. I also checked the fuses (#4 & 5) with the test light, light switch off they had no power. Light switch on and they both have power. It seems like my problem is at the socket. Would this be a result of the multi-function switch or the body control module? Or could it be a fusible link or something else simple? What do you think? If I get time tonight I may pull the steering column apart and have a look.
Thanks,

 

[kb0nly]

Hmm... You turn the switch on and there is power everywhere but at the lights? Then that rules out the multifunction switch if everything has power and the relays are turning on.

I would almost bet on a bad connection or something. No power at the low beam wire at the headlights but there is power off the fuses correct? Then you have a problem somewhere between the fuse box and the headlights. The multifunction switch wouldn't be the cause because the relay turns on and sends power to the fuses, the fuses then supply power out to the headlights.

I will have to look at the FSM a bit but the best i can figure is a broken wire or bad connection somewhere if your checking the low beam wire at the headlight connectors and not seeing power.

 

[kb0nly]

Ok... Checked the FSM.

The MFS tells the BCM to turn on the Low Beam Relay, and the relay then feeds fuses #4 and #5.

Stupid question but you did check both sides of each fuse with the test light correct? I only ask because i have made the mistake myself of being in a hurry and checking only one side with the test light and the fuse was actually bad and the other side was dead.

If your fuses are good and the relay is switching power to them then there is not a MFS or BCM or relay problem. It must be a wiring problem between the fuses and the lights.

If checking the plug at one of the headlights there isn't power then go back in the harness a bit and probe the low beam wire to rule out a bad plug. Otherwise your going to have to trace the low beam circuit all the way back to the fuse in the panel.

If you have a VOM, Volt Ohm Meter, with a continuity check on it pull fuse 4 and 5 and then use your test light to see which side of the fuse socket is the supply and which side goes to the lights, once you know that use your VOM and check for continuity from the light side out to the plug at the headlight. I usually use a long clip lead i made for continuity tests like this but a piece of wire stripped back and pushed into the side of the fuse holder that goes to the wire feeding the lights to extend your meters test lead would also work. The lowbeam wires at the headlights is Violet and Violet/Red.

 

[1of1547]

Thank you so much for your trouble and research. And you are correct about the fuses. I learned the hard way several years ago. But you probably will not believe this, but both bulbs were blown. I was checking everything as you said. And when I pulled the first bulb it showed no continuity. When I pulled the second bulb I could see the filament was blown. I checked both of the outside poles and they have power as I pulled the switch for highs and lows. I apologize that I jump to such a quick conclusion. But in all my years of missing with motorized things, I've never had both bulbs blow!!! But you live and learn everyday.

One interesting note though. It feeds the fuses from different sides of the fuse. I think the upper fuse was feed from the right and the bottom from the left.

Thanks again for your help!!!

 

[ridenby]

Two at once is weird.....except in the KJ world. I swear these things remind me of IH pickups/scouts.

 

[kb0nly]

Cool and weird at the same time... LOL