I'm having some electrical trouble with my wife's '06 Navi, which we've had for about a year with no issues up to now. I've searched the forum and no two electrical issues seem completely alike, so I've covered the common bases, but still having problems. Here's the run down of the chain of events. (sorry for the long post but I'm trying to be thorough)

My wife went through the car wash. A few minutes later, the CD player acted up, but straightened out (not sure if its related or not, but it's the only problem we've had with it). After driving about 5 minutes through town, she parked at a house and went in for just a minute. When she came back out, the car would not shift out of park. I pulled the trim ring around the console gearshift and used the override switch to get it home. I found the #6 fuse in the passenger kick panel was blown, which controls tail lights, marker lights, and dash illumination lights. It was a few days in between the issue and getting around to work on it and I replaced the fuse and all was good. I couldn't find any signs of leaking anywhere.

She drove it for another couple of weeks (even went through the car wash again without issue) until it rained one day. After driving about 25 minutes in the rain, blew the same fuse. I quickly replaced it, but it immediately blew again after starting the vehicle. Let it sit for a few days (to dry out), replaced the fuse and all was good again. Still couldn't find signs of leaking.

I poured water along the front of the sunroof to see if the drains were plugged and both ran free.

I took the car to the dealer to check the windshield. They said yep, it leaks and set up an appointment for their glass guy to come fix it a couple days later. He showed up and decided it wasn't leaking. So they took down the headliner and pieces off the dash and went around and under the car with a pressure washer. They couldn't get any water to leak in anywhere they could tell. They were stumped and didn't even know what else to do. I told them to put it back together and I picked it up the next day.

The following day, my wife was driving to work in the rain and about 20 minutes in, the fuse blew. When she got home that night I looked and felt around for wet carpet or anything. I did find some moister behind the glove box and on the passenger floor board, about above where your left toe would be if you were riding there, where I'm assuming what is the heater core goes through the firewall. I assumed it was condensation from the AC, but didn't know for sure. That was Friday and we let it sit all weekend.

After work today, I checked for water/moisture again. The foam gasket that goes through the firewall was still a little wet, but that was the only moisture I could find on the entire car. I replaced the fuse and all seemed to be fine. I headed to town to go to the car wash with the intentions of spraying locallized areas of the car until the fuse blew to try to narrow down my search. I even put the heater on high to try to dry out was I'm assuming to be leftover AC condensation. But, about 10 minutes into the trip, the fuse blew and it is dry here today.

I turned around without going to the car wash and took out all the parking and tail lights to check for moisture, I looked with a flashlight underneath, in the fenders, checked the trailer wiring harness, and kept looking under the dash. I can't find any other water or moisture other that what I mentioned, nor do I see any signs of water getting in anywhere like tracks in the dust or anything.

So, either there was still moisture somewhere or the problem is not from water. But I think it's got to be too big of a coincidence not to be.

Anyone have any ideas? Should I have the windshield sealed again anyway and hope that fixes it? Should there not be any moisture where I found it on the passenger floor board? Any ideas or help is greatly GREATLY appreciated as this is driving me nuts!!! Thanks fellow FTE's!

 

The turn/brake light wires run through the MFS on the column to give you turn signals. That being so, means that the wires for the tail/brake lights also run through the column. There are known electrical issues with the turn/brake light failure due to the tilt column movement tugging on the wires going to the MFS connector. I'd start with the column area and look for abrased wires, loose connectors, or wires that get pulled when the column gets tilted down.

 

Thanks, I'll check that. Just a note, the turn signals and brake lights still work (they are on a different circuit from the parking/taillights). Not to say what you suggested can't be a problem, just making clear for help on diagnosis.

 

Nevermind don't bother. I didn't realize it was just the parking lights that were blowing. I misunderstood and thought everything was going out because of the issue with not being able to shift out of Park. Shifting out of Park is tied to the brake circuit since you have to step on the brake to shift, so I though the blown fuse was handling that as well.

 

I went and looked it up and the #6 fuse feeds the following circuits: Headlamp switch (park lamps and switch back lighting feed), Park lamps, License lamps, Fog lamp relay coil, Trailer tow electric brake controller (illumination), BSM (auto lamp park lamps), Floor console gear selector lighting, Fog lamp indicator.

Have you inspected the license plate lamp to see if water is getting in that?

 

Actually no, that is a good idea. I checked the tail lights and trailer light leads, but I didn't even think about license plate light.

Also I talked to the mechanic yesterday that worked on it. He said they concentrated their efforts around the winshield and front end. So, my next focus is going to be around the back end of the vehicle. I also just noticed that the lift gate motors wouldn't run to lift or close the rear gate while the fuse is blown. So I'm going to try to get access to them too and see if there are any signs of water in/around them.

 

Well now I'm completely stumped. Went to the carwash and went around the car with the wand.........didn't blow the fuse. So, I took it through the automatic......didn't blow the fuse. So back to the wand.......still didn't blow the fuse. I checked everywhere I could think of for signs of water and nothing. Let it dry for a couple days and took it to another car was last night (the one my wife went to when the first fuse blew) thinking it must shoot water in just the right direction. I went through it 3 times in a row without blowing a fuse. It's either healed or there is something about driving in the rain I can't seem to replicate. So I put all the interior trim back together and we'll drive it and see what happens next time it rains. Very frustrating and puzzling.

 

But think of how clean the car is!

 

Hi Humphrey,
Have it happend again? I'm having the exact same thing on my 05 navigator, but I can't find the leak....

 

The brake switch runs 4 wires through it. Constant 12v that lights your brake light wires when you.... You know. The 12v feed off the ignition,and that closes a circuit to you shift solenoid. That's all I know.