Finally happened to me, Dash/Tail lights are out (3 Viewers)

[NLXTACY]

It happened on the way home from Tahoe a little over a week ago. Didn't really pay much attention to it again until just now because I haven't driven at night til now. Ugh, time to jump in. I read up a few threads and I've checked off most of the common issues. Still haven't found the issue but I'm narrowing it down at least.

The 15A TAIL fuse was blown and after two more attempts, I think I could narrow it down to a short

Next up was the TAIL relay. Removing it was a pain in the ass because my shoulders are too damn wide to be struggling under the driver's footwell. That sucked. To top it off I first removed the wrong relay because it wasn't on my EWD. It was the one ABOVE it that I needed, the 3-pin relay.

 

[NLXTACY]

The relay was tested by supplying power to pin 2 and ground to pin 1. Buzzzzzzz. Good to go.

 

[NLXTACY]

Checkout the fuseible links and all is good and brandy spanking new

Checked out the trailer wiring on the outside of the truck on the underside. No fraying whatsoever and the wiring itself is just ziptied out of the way. No issue there. I did a quick check behind the quarter panel and didn't see anything striking but now I need to remove all of my crap in the quarter panel mount to even get to it. So that is the next step.

 

[thebus]

My trailer wiring was the culprit..the splices kept shorting it out behind the tail light..fun fun! ripped it all out and repaired

 

[NLXTACY]

My trailer wiring was the culprit..the splices kept shorting it out behind the tail light..fun fun! ripped it all out and repaired

Yeah I’m gonna remove the corner light assembly and the Quarter Panel Mount. I need to open up those stupid little black boxes down there.

Someone else suggested the combination switch stalk at the steering wheel. Never heard of that as a potential but I’ll check that next.

 

[thebus]

Yeah I’m gonna remove the corner light assembly and the Quarter Panel Mount. I need to open up those stupid little black boxes down there.

Someone else suggested the combination switch stalk at the steering wheel. Never heard of that as a potential but I’ll check that next.

I always try to keep it simple..it has to be! KISS that is my new motto for 2018

 

[NLXTACY]

I always try to keep it simple..it has to be! KISS that is my new motto for 2018

I’m not sure my brain works that way

 

[inkpot]

Yeah I’m gonna remove the corner light assembly and the Quarter Panel Mount. I need to open up those stupid little black boxes down there.

Someone else suggested the combination switch stalk at the steering wheel. Never heard of that as a potential but I’ll check that next.

I had that same problem several years ago. As it turned out, I had landed on a rock pretty hard and bent my tailpipe up above the early Slee rear bumper. That directed all the heat up into the rear quarter area. Along with melting my right tail light and the small plastic bits on the right end of the tail gate, it melted some of the trailer harness wiring inside the bottom of the quarter panel enough that it shorted out on the inside of the body. Replaced the trailer light harness with a good spare set and replaced the fuse; all was OK again.

 

[NLXTACY]

@inkpot I didn’t keep the exhaust in mind. I’ve also bashed mine plenty. I’ll do a thourough check during sunlight.

 

[MattL]

Trailer harness rubbing on the receiver hitch was my issue. Went nuts looking in the tail light area :/

 

[inkpot]

@inkpot I didn’t keep the exhaust in mind. I’ve also bashed mine plenty. I’ll do a thourough check during sunlight.

I had already cut off the resonator, but I bent the last 6" up just enuff that it went above the beg wide pan under the RR corner. I would never of imagined how much heat come off this exhaust. It even melted the corner of my flair. Well, it is my fault, I suppose. It was late night coming back to town over Mt Ord and thru the slaloms marked 55 and 65 mph. I know the road well and normally cruise down it at 20 over. ITs fun to play traffic tag with the Vetts and Bmers that feel brave at 10 over.

 

[Tools R Us]

The combination switch, relay, fusible link are all upstream from the Tail fuse, so even if shorted, would not blow the Tail fuse. The first thing to check is any added aftermarket wiring, on your rig that could be a daunting job! The tail fuse runs all of the marker lights, like the lights on the gay r bee bumper?

 

[jonheld]

On my 91 I lost tail/gauge lamps on the way to New Hampshire due to an exhaust leak melting the harness that runs under the truck between the two rear quarter panels. That was fun.

 

[Mr Cimarron]

I had similar issue from my auxiliary harness rubbing on my metal battery holder up near my headlight. Although I can’t remember what fuse was blowing I do remember that I needed to fix it at work in order to drive home with proper lights.

 

[BILT4ME]

Did you just check the taillight bulbs? Or did we go right to overheating............

Most vehicles, when a taillight bulb is out, it takes out the dash lights so you know you have a problem. I don't know on LC's, so I'm offering a suggestion.

 

[NLXTACY]

Well CRAP! I thought I had this fixed but it just started happening again. Pop in a new fuse and as soon as I turn on the headlights the dash lights up for a split second then pops the fuse. Every single time. Damn this is frustrating.

 

[LINUS]

Have you still got any sort of towing / trailer harness in your 450?

Seems like those all came with a receiver & a “L” in Lexus font plug in it.

If you do, that’s where I’d want some attention 1st. - you did the due diligence up in the relay box area.

 

[greentruck]

Yeah, several mentions of the tow harness. Mine looked fine, too, but the little black box that's embedded with it proved to be the culprit. Unplug the harness, problem solved, so R&Red tow harness.

 

[NLXTACY]

Yeah, several mentions of the tow harness. Mine looked fine, too, but the little black box that's embedded with it proved to be the culprit. Unplug the harness, problem solved, so R&Red tow harness.

I’ll take another look at it.

 

[baldilocks]

So, I recently had my 93 dash apart for overhaul so I pulled the dome fuse to shut down the stuff that’s powered with the door open for a week and, while I was in there, I noticed the plastic casing of one of my head light fuses was melted but the fuse was still good.

Investigation revealed that the one half of one side of the fuse recepticle was mashed and probably making poor contact with the fuse and possible increasing resistance or arcing maybe, i’m not sure.

On another occasion, I turned the key and nothing happened. I tracked it down to the ign fuse in the interior fuse panel being loose fitting. Yes, the Japanese fuses are thicker than the Chinese replacements we buy downtown.

Wheel studs aren’t the only thing that’s wearing out.