Instrument cluster and dome lights wont turn on

[dankwun]

A few months back i was having a problem with my dome lights not turning on when i opened my doors.. Then eventually they wouldn't turn on at all, so i tried dimming my cluster lights and the dimmer switch would not work.. Then the next day my dome lights and instrument cluster lights would not turn off i had to pull the fuses and park my car for the night. I took out the dimmer switch and tried to clean it and put it back in and then none of the lights would work.. So i went and bought a new dimmer switch and hooked it up but still nothing. So then i tested the ground tonight that goes to the dimmer switch and it is fine. Has anyone else had this problem?? any possible solutions?? i really don't feel like following theses wires through my dash and replacing them.. Please help me!! thank you..

[vegasmarauder]

The headlight switch really acts as ground signal to LCM (lighting control module) to send power to the dash lights. The LCM also reads the door latch open ground signal to turn on dome lights by a ground switch in the latch. There are about 4-5 different fuses that supply the LCM with various power sources. Any one of them could be bad or not making a good contact in the fuse holder, which can cause erratic light operation.

A quick test at the headlight switch is to ground the white with black stripe wire. Just jump it to the black wire at the connector. If you get park lights, the switch is bad.

The dome lights go thru the dimmer only to turn on/off without the door triggers. The dimmer sends a ground to the LCM to turn the interior lights on. The fact that none of the doors turn on the lights indicates a no power or switching problem in the LCM.

If the LCM is getting power from all the relavent fuses, then the LCM is failing/failed.

There are more tests, but its a bit too complicated to write up in a post but this should give you a direction for the park lights.

[dankwun]

Thanks for the response. I was wondering though, you said to just ground out the black/white wire that goes to the headlight switch and is the park lights come on the switch is bad, so by park light you mean running/corner lights? For a few months before this problem my interior lights didn't come on when i opened my door or they would flash.. Or i would have to slam the door repeatedly to get them to some on. I was thinking the wire that turns the lights on when the door is open was loose or something. But you made a good point because my dome lights dont turn on no matter what door is opened.. oh and the other thing is, when i unplug the harness from my headlight swtch my headlights and running lights turn on. So i dont get hom im going to ground out the wire to see if the running light turn on when they are already on.. Please help me.. Im lost on this situation and its driving me crazy.. i miss my green guage cluster and my LED dome light..

ps. the two lights with the switch in the front of the overhead console work fine when i turn them on.. idk if this would help solve the problem.. It just makes me think there is no way it is a switch if they work.

[Paul]

I would guess there is a problem with your LCM.

[fastblackmerc]

Could be an LCM problem, but most likely it's a problem with the switch inside the door for the interior lights.

[vegasmarauder]

Approach this as 2 seperate issues. Park/run/dash lights on seperate circuit from dome lights. Normal for lights to come on with switch unplugged. Jump wires with switch plugged in. If it works, suspect bad switch.

The dome light is triggered by door open switches..drivers door on one feed, rest of doors on another. Usually a bad door switch the lights won't come on when only that particular door is opened.

A failure of the entire dome circuit can be fuses or connection to LCM. Sometimes alarm installers tug on the wires at the LCM and they don't connect. Check the LCM plugs are fully seated too.

[dankwun]

okay so i have an update on this... It was actually really strange. I went on vacation for 8 days and then tonight when i got home i went to go work on fixing this problem, I tried to start my car and it killed the battery but then as i was getting mad that the battery died i noticed that right when it died my gauge cluster lights worked.. then i realized that all my dome lights were on as well.. So i jumped my car and put the old dimmer switch back in and now everything works fine.. its almost like if just disconnecting and reconnecting the battery would have solved my problem. Im hoping that the dealership will take back the new switch that i bought.

But now i have a new problem and dont really wanna start a new thread and flood the forum. So now that i fixed all this i noticed that my EATC lights are back on but none of the buttons on it do anything. I tried the outside temp button and cant get it to display on my EATC display. Same with the a/c, heat, etc. Is there a different fuse for the buttons on the EATC and another fuse for the lights on the EATC?? I tried pulling the harnesses out of the back and replugging them but that didnt solve my problem. =\... PLEASE HELP ME!! thanks in advance..

[fastblackmerc]

okay so i have an update on this... It was actually really strange. I went on vacation for 8 days and then tonight when i got home i went to go work on fixing this problem, I tried to start my car and it killed the battery but then as i was getting mad that the battery died i noticed that right when it died my gauge cluster lights worked.. then i realized that all my dome lights were on as well.. So i jumped my car and put the old dimmer switch back in and now everything works fine.. its almost like if just disconnecting and reconnecting the battery would have solved my problem. Im hoping that the dealership will take back the new switch that i bought.

But now i have a new problem and dont really wanna start a new thread and flood the forum. So now that i fixed all this i noticed that my EATC lights are back on but none of the buttons on it do anything. I tried the outside temp button and cant get it to display on my EATC display. Same with the a/c, heat, etc. Is there a different fuse for the buttons on the EATC and another fuse for the lights on the EATC?? I tried pulling the harnesses out of the back and replugging them but that didnt solve my problem. =\... PLEASE HELP ME!! thanks in advance..

Do you have an owners manual?

All the fuses are listed in it.

[IwantmyMMnow!]

Pages 146 &147 if you do...if not, see pics below...

[dankwun]

Thank you sir.. :)

[bugsyc]

Yesterday night I noticed my instument cluster was off.every thing else worked..I replaced fuse #21 which tested bad.I Didn't go out last night..This morning the same fuse #21,a new 15a was flashing red.took it out and sure enough it was blown..Any ideas what the problem is???interior lights all work

[fastblackmerc]

Yesterday night I noticed my instument cluster was off.every thing else worked..I replaced fuse #21 which tested bad.I Didn't go out last night..This morning the same fuse #21,a new 15a was flashing red.took it out and sure enough it was blown..Any ideas what the problem is???interior lights all work

You have a short......

[bugsyc]

How would I go about finding the short?or is this something I need to bring to mechanic who specializes in electrical issues No more warranty left..

[fastblackmerc]

How would I go about finding the short?or is this something I need to bring to mechanic who specializes in electrical issues No more warranty left..

You can disconnect everything on those circuits, replace the fuses then connect the things one at a time to see what blows the fuse(s).

The first place I'd look is the drivers side visor. Remove the mounting screws and see if the wire is frayed or pinched.

[bugsyc]

I took apart the visor,all is well there..fuse 21 says interior illumination,parking lights,AUTO SUN LAMP COLLECTOR
sun collector...the parking lights are not working,could it just be a bulb?IS IT THE SAME BULB AS THE TURN SIGNALS?BECAUSE THEY WORK

[bugsyc]

where is the sun collector,or meter or whatever it is that tells the lights to come on automatically??

[fastblackmerc]

where is the sun collector,or meter or whatever it is that tells the lights to come on automatically??

The middle of the dash...

[bugsyc]

where in the middle?above the clock?above the radio?above climate control??

[fastblackmerc]

where in the middle?above the clock?above the radio?above climate control??

Look for the flashing red light.....................

[bugsyc]

would that be the flashing red light on top of dash,drivers side? Because mine is still flashing.that is supposed tobe on the same fuse 21 that keeps blowing..I need to take my kid up to college in 10 days and have to get this fixed..can't afford the dealer..I don't know what to do..The only thing I did to the car was change the battery connections..I looked and looked everything looks good..car runs fine..I'll check all the fuses again..

[bugsyc]

Yes Sir,it was a short.Took it to my mechanic,he also said it was a short.4 hours later,after removing instrument cluster,radio,clock,trim and testing wire after wire,he found the short in the right tail light harness...what a nightmare..If I had gone to Ford,who knows what they would have charged..he told me to get a new right tail light harness..I'm going to do that right now...Glad that's over..

[fastblackmerc]

Yes Sir,it was a short.Took it to my mechanic,he also said it was a short.4 hours later,after removing instrument cluster,radio,clock,trim and testing wire after wire,he found the short in the right tail light harness...what a nightmare..If I had gone to Ford,who knows what they would have charged..he told me to get a new right tail light harness..I'm going to do that right now...Glad that's over..

Good luck getting that harness. Might be easier to repair it.

[bugsyc]

tousley ford...$38

[bugsyc]

Fast Black Merc right again..Tousley Ford cancelled my order.Part no longer available

[fastblackmerc]

Any decent mechanic should be able to rebuild a harness.