On the way to work this morning I noticed I had no passenger side turn signal/brake light, when I turned on the signal for a right turn and the light was blinking rapidly. I thought the bulb burnt out so I bought a new pair. Even with the new bulbs the brake light and turn signal still don't work but the parking lights do! I tried looking for damaged wiring near the socket and underneath the rear of the truck but didn't see anything. Is there a fuse that went out that I'm not aware of? What else could it be?

 

99,

By your description you have a short to ground in that circuit. That will cause the flasher to run fast. To confirm this, test the driver side to see if it flashes as fast. Do you have the tow package? Have you added any electrical accessories? Have you changed the bulbs recently? Do you go off road?

Regards

Jean Marc Chartier

 

Hey JMC, the drivers side is fine and all the other lights are fine too. I don't have any tow package, just the standard 4 pin harness plug on the rear bumper. I noticed the rubber cover was off a few days ago. Could moisture getting in have been the culprit? If so what should I do? Anywhere else I should look for something? Oh and no offraoding for me, I don't want any square wheels!

 

I have a 98 expy and i have the same problem except on both sides. it works fine when its warm. so thats what i was thinking would cause it. my dad is in San Diego until friday so when he comes home we'll look for anything that may seem out of the ordinary but where would we look?

 

99,

Because the driver side is fine that eliminates the flasher. Are both side rear brake lights inoperative?

Regards

Jean Marc Chartier

 

No, only the pasenger side brake light is inoperative. Thats what has me confused why only the brake light is not working and not the parking light too or both brake lights.

 

99,

When did all this start? I noticed you have the clear lense tail light. How many bulbs does it have? 3? Did you have to rewire any sockets to make it work? A short to ground is the most likely as the Stop and Turn bulb are the same one. If both are not working then what is common to them should be looked at first.
You will have to probe the circuit and check for continuity to ground. There should be 3 wires going into the bulb socket. One is ground one is power to the parking light circuit and the other is power to the stop/turn circuit. The ground wire (black) should have continuity to ground with the bulb removed. The orange with light blue striped wire should not have continuity to ground with the bulb removed.

Regards

Jean Marc Chartier

 

All this started on Monday. Yeah I have the 01 L taillights, but I did no re-wiring. All I did was connect the brake/turn signal and reverse light sockets to the L taillight housing and left the remaining parking light socket tucked under the taillight. Where do the wires start from? The power distribution box in the engine or the fuse panel inside the cab? What fuse number should I look at? My truck never came with a manual! Thanks for the help, JMC!

 

sound's like a broken wire at the back of the multifunction sw. OG/LB. the rear light's are on diff. circuit than the front. due to the tilt wheel. these wire's get a work out. i'll bet your problem is there. try tilt in diff. postition's and see if it light's. if not pull the cover. and check that wire. it could be broke inside and you not see the break. so look at it close. good luck.

 

99,

If it was a fuse both sides would not work. The brake/turn light is wired through to the Multifunction switch. The orange with light blue stripe wire goes into the switch. Remove the bulb from the tail light and disconnect the multifunction switch. Test that wire for continuity to ground. There should not be any continuity. If there is it is shorted to ground. If the is no continuity then the multi-function switch is probably defective.

Regards

Jean Marc chartier

 

ok well my dad tried a little squirt of WD40 and its worked wonders so far probably just a dirty contact down there. so try that and call me in the morning.

Dr. Jon

 

Well I ended up taking my truck to the dealership and had it fixed under warranty (which unexpectedly ended today ). But anyway, it turns out the pass. side brake/turn signal wire came loose at the multi function switch! So everyone who suggested it was the switch was correct!