My wife and I just picked up her new / used 2008 Eddie Bauer Explorer last night and the dealer said that they repaired the issue that was with the front dome / map light and vanity mirror lights in the sun visors. Well, when we picked up the car last night, the blasted lights still didn't work. They said to bring it back and since it has the certified pre owned warranty, they will fix it no charge. I checked the owners manual to see which fuse it is and the fuse checked out good. Also on that circuit is the puddle lamps, homelink, interior lights, instrument panel lights, and all them work with the exception of front map lights (front dome light) and the visor mirror lights. The fuse is ok for the interior lights. Anything else I should check? My gut feeling is that there is a short or broken wire some place. Should I wait the week and let the dealer mess with it and be without a vehicle for who knows how long or should I try to find the problem? Im a little concerned messing with anything as the vehicle has the canopy / curtain air bags which I know is up in the headliner and A post.

Your thoughts are appreciated.

 

Since the fuse is okay, you don't have a short. A loose connection or broken wire is possible though.

Per the wiring diagram, it appears 15A fuse F23 is the fuse that provides power to the map lights and the vanity lamps via the Smart Junction Box (SJB).

The map/dome lights have two separate feeds from the SJB, both powered by fuse F23. One feed (yellow/gray wire) should be hot when a door is opened. The other feed (green/violet wire) should be hot all the time. Assuming the dome/map lights do not work with the switch in either the "Dome" or the "On" positions, I'd suggest you check the grounding circuit. If you're comfortable taking the bulb covers off, at least for the map lights, you could start by checking for a good ground at the lamp sockets. It appears all these lights have a common ground splice. If you find they are missing ground, that will at least give you a talking point with your dealer if you decide you don't want to fix the ground wire yourself.

-Rod

 

Thanks for the reply. I did do a continuity test of the 4 wires up at the plug for the map light down to where the connection is by the A post where it connects in to what I am assuming is the main harness. All 4 wires tested good in that section. I also did a continuity test across the light bulbs in the map light to double check that the bulbs themselves were good. I wonder if I hooked up a jumper wire as a ground from the map light bulb and see if that might work?

 

I did move the dimmer switch to the "on" position once and it did not work. Tried it again and then it did work. Seemed to work for the rest of the day today. However, the constant hot wire does not seem to be the circuit that is working properly though. If the map / dome light shares a common ground, I doubt that it would be a grounding issue.

 

Unfortunately it sounds like you may have an intermittent connection which could make it more tricky to troubleshoot. I agree with you that based on your findings when using the dimmer switch, the issue is probably in the green/violet wire. If it would help, I can provide you with pinout information for the SJB so you can check for continuity between the SJB and the dome light.

-Rod

 

Rod, if you could that would be appriciated. I popped off the side access panel on the dash (triangular shaped plastic piece) and tested the connection from where the main harness meets the A post for the wiring that goes from the A post connection up to the plug for the map lights and that green/purple wire was good from the A post up to the map light. Actually, all 4 of the wires were good going up to the plug that plugged into the map light. If it is anything, I think it is somewhere between that connection and somewhere in the main harness.

 

Since I made this JPEG in Portrait mode to capture as many of the pin labels as possible, the appearance of the connector is a bit distorted. You're looking for terminals 8 and 23.



-Rod

 

Ok, so im guessing the yellow with gray tracer should be constant hot and the green with violet tracer should be hot when the door is opened?

 

See post #2 above.

-Rod

 

Thanks for the diagram. I popped down the small console that has the home link, switch for the moon roof, and the map lights and tested the yellow wire. It has constant 12 volts with the door open. The green wire with violet tracer had zero volts. Funny thing is that I pulled the connector back in, had only one light come on for the interior light (pass side bulb but reflected down to the driver side) and then I tried the vanity mirror lights, they worked and then stopped. At the same time, the front interior light went out. Out of curiosity, I tried both map lights which then worked. I then tried them again and worked. I unplugged the connector to find out why the map lights worked but not the interior lights and then after plugging it back in the interior light (still only one side) worked but not the map lights or the vanity mirror lights. Something aint right for sure.

Also, when I pulled out the #8 fuse (15 amp) I lost all power essentially to the interior. Turn the key nothing would happen, no dash lights, power seat wouldn't go back for the easy exit option, etc. I tested the two wires where the fuse was and had 0 volts. I put the fuse back in, everything worked again.

Pulled the #23 fuse (15 amp) and had 12 volts across where the fuse is.

 

Ok, just went out and tried it again. Map lights now both work but the front dome light is not working as well as the vanity mirror lights. The green with violet tracer wire still has 0 volts at the map light. At the connection down by the A post and the dash, the green with violet tracer has .55 volts. I tried doing a continuity test of the ground wire in the harness and at the connection where the dash and A post meet, and the ground (black) wire in the dash harness part and with the continuity tester hooked up the wire harness to the tester with the other lead going to bare metal, it was ok. Previously checked was the harness that goes up the A post up to the console which also had all wires checked for continuity and all were good.

I am totally baffled as to why the green wire works sometimes and sometimes it doesnt. Is there some kind of a relay that works in conjunction with the green with violet tracer wire?

 

The green/violet wire I believe is controlled by the Battery Saver Relay which I believe is internal to the SJB. The Battery Saver Relay is the relay that will turn off the lights if they are left on for something like 40 minutes after the key is removed.

-Rod

 

Update - Well, as I was taking our 1 yr old to the doctors today, while I was at a stop light I decided to try the map lights and see if they still worked or not. Nope! They are dead again and now the dome light isn't coming on. Seems as if everything died all together again. Looks like it is the dealerships problem since they said they "fixed it" before we took delivery and when we went to pick it up, it still wasn't working. At least it is a Certified Pre - Owned car and has the extra warranty!!!!!!

 

Well..... heard back from the dealer today and the service manager said that the new sunvisor with vanity mirror and light seemed to be the problem as they said there was a short in the wiring which was causing all the problems. They had to order a new sun visor and said it will be in tomorrow. The reason why the sporatic working of the dome light and map lights was because there is a module that senses the positive and negative current and will limit or shut down certain things if there is a short. Hence, exactly what was happening with our car. The module was recently replaced (first time we had the problem before we took delivery) and was around $300 from what the sales manager told us. The service manager said that the module was ok this time but had to be reset using a computer. Electrical things like this make me love my 69 Charger more and more. Tomorrow I shall see if it is fixed or not and will report more then. Till then, wish me luck!

 

Good luck, hopefully they got it fixed this time!

-Rod