So on the way home the last two nights I've notice that my 3rd brake light only works some of the time. Replaced the bulbs with the known good bulbs from my other D but no change. When it's not working, if I hit a good bump while my foot is on the brake, it will come on and stay on for awhile. When I get to the next stop sign, it might work, might not.

Sounds like a ground issue to me, but my quick 30 second once over (all I had time for) didn't really reveal any obvious trouble spots to investigate first.

Before I really dig into the wiring too deep, was just wondering if there were any known trouble spots that are prone to corrosion or plugs coming loose or whatever else... Hate to kill an afternoon tearing the thing apart and tracking it down if this is a known issue...

I get off work right around the same time the bars close (the time of night when they will pull you over for absolutely anything), and my route home takes me through a small town with a bored cop. If I don't get this fixed soon I can foresee many "friendly visits" with him in my near future. I'm sure he's probably a nice enough guy, but when I get off work at 2 am I'm really more in the mood to just go home in peace and get some sleep....

 

definitely sounds like a ground issue, i would pull the plastic off the inside of the rear hatch and follow the ground from the light and make sure its good and clean and tight

 

How about the switch behind the brake pedal?

 

I'll check it out, but my gut feeling is that it's not the problem, simply because the two lower brake lights work 100% of the time. Checked that a couple of times when I got close to a building where I could see the rear lights reflected in a window... If it was the switch I would think the problem would affect all 3...

 

+1 Dan, that's what I was going to say.

 

based on what he said about the other two lights working all the time id say the switch is probably fine, since its ONLY the third light id definitely be looking for a ground

 

Nope, the switch looked fine. Shouldn't really be that anyway, it would be just plain shoddy engineering to have separate wires for each brake light running all the way up to that end of the car...

On the way home from work tonight I had to stop for gas, so I pulled that trim panel off to take a quick look. I was using a piece of **** $2 flashlight that I grabbed when I paid for my gas, and it was cold as hell, so once again I didn't dig very deep, but I did notice that right next to the housing for the third brake light is a pretty big wiring plug.

Given that I also have a dead rear wiper, my guess is that harness controls everything in the liftgate, and that the bad ground is probably right there. Soon as the sun comes up I'm going to go unplug it and see what there is to see....

(****ing second shift job... Hate this ****... Two more weeks and I get moved to my first shift position that I won my bid for, then I can function like a normal human again... Feel like a little kid waiting for Christmas to come.... LOL....)

 

Ground or power would both cause your issue. Don't turn a blind eye to the power side. Do a wiggle test on the harness and of course check out that connector. Also check out the electrical testing write up and grab a cheap meter. If it is a long path to ground you may want to test for voltage throughout the ground wire

 

Have a meter and I'm more than familiar with testing electrical systems. It's a big part of how I've made my living for the last 20 years (before the economy tanked and people in my line of work all got laid off... Things are looking up, though. Companies in my area are finally starting to hire for the high dollar jobs again, so I should be back to living like I'm used to sometime this year... ).

My big issue is that my wife and I are down to one vehicle ever since the tranny in the 98 D shot craps, so we have to share the 99.. She leaves for work at 6 am, comes home about 3 pm, we chat for 5 minutes and then I have to haul *** to get to work on time. I come home around 3 am and then we do it all over again. So I have a 3 hour window where the truck is actually home and I can do anything with it, and it's in the dark at the coldest time of day during an Iowa winter. Not to mention that after a 9 hour shift in a packing house my old-fart *** barely has the energy to make a sandwich, much less do any more real work... (Thus my excitement to finally be going to first shift... )

I can track this down as soon as I get a chance. My main purpose was the hope that someone would chime in and say "Oh, yeah, these things leak at this spot and this connection gets corroded."

I knew it was a long shot, but hey, ya never know, right?

 

If it makes you feel any better my 3rd light hasn't ever worked since I bought the D in 05'. I've never cracked it open to check it out. Probably just a burned out bulb but who cares. I've been pulled over 3 times with that light out and never been bothered about it.