Dash Lights Out

[99ExploratorySUV]

So, today, all of a sudden, my dash lights, are all out. This includes the instrument cluster and the HVAC controls and even the ones in the back seat for the heater. However, my E-brake light, turn signals, battery light, check engine light, and every other light is still functioning in the dash. The speedometer and tachometer are still functioning as they should, but are not lit up. Overhead console and dome lights are all working just fine. My headlights and tail lights are also functioning as they should. I checked all fuses under dash and under hood. All are perfect. And yes, my dimmer is all the way up. I am absolutely baffled. What is going on? Please help. I have a 1999 XLT. If anyone can help, I'd really appreciate it, cuz I can't tell how fast I'm going at night.

~Kyle

 

[99ExploratorySUV]

bump

 

[Cobraguy]

The fuse in question is fuse 26. Make sure you use a test light or meter to check the fuse. Lots of fuses that look good...but aren't.

First item after the fuse is the Battery Saver relay. That is turned on by the GEM. (door switch, etc) The controlled circuit leaves the Battery Saver relay and splices out to multiple locations including vanity lights, map lights, electric shift control, etc. So if any of those lights are good, then the Battery Saver relay is good. It also goes to the dimmer module and interior lamp relay. The interior lamp relay is also controlled by the GEM. It supplies power to the dimmer module for the instrument lights, and goes to some rear interior lights, running board relay if equipped, etc. If your rear interior lamps or cargo lamp is working, then the interior lamp relay is good. That would leave the dimmer module...which wouldn't be uncommon. Grab your wallet...the price for new will get your attention. So make sure of your diagnosis.

By the way, if the GEM isn't grounding the relays to turn them on, then it's bad. Just something else in the mix...

 

[99ExploratorySUV]

Thanks so much for your detailed reply. I just checked fuse 26 and replaced it. However, it didn't fix it. My cargo lights are all able to come on, but my dash lights are still out. My map lights all work too. It sounds like it must be this dimmer module. I was looking on www.genuinefordparts.com for this particular item, but can't find it. Do you know if it has another name? My Ex is a 1999. I tried searching through the categories for it, but I don't know what it would be under.

 

[99ExploratorySUV]

Wait hold on, I just checked autozone.com. Is this it? And is this that price you were talking about? http://www.autozone.com/R,261928/ve...partType,00612/shopping/partProductDetail.htm How hard is it to replace? I also have another question. How is it that the dimmer is bad if when I push it all the way up till it clicks, it turns on all the dome lights? Shouldn't that mean it's working? Or no?

 

[sean99]

Mini fuse 11 in the engine compartment solved my dash light problem...

 

[sean99]

http://cgi.ebay.com/ebaymotors/99-0...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

 

[99ExploratorySUV]

Update! I took apart the dash to get access to this dimmer switch right next to the headlight switch. It wasn't too hard, following the Haynes manual. It just takes patience to get at all the bolts before you start pulling things apart. Anyway, I pulled out the dimmer switch, and it looked just like the picture from Autozone. I was begrudgingly about to order it, when I thought, hmm.. maybe I could clean it? So i remembered that I had a can of Mass Airflow Sensor Cleaner in the garage, and it can also be used to clean other delicate electrical connectors. So I soaked the connectors as well as the exposed copper on the side of the switch with the cleaner. It evaporates almost instantly. So after it dried, I put it back in and it works!! So I'm really happy that I didn't have to spend anything. If anyone else is having this problem, try cleaning the dimmer switch first before you drop a hundred bucks!!

 

[Cobraguy]

That's great news! And it's nice to see a procedure followed and have it be correct! LOL

Good diagnosis.

 

[azzey]

So... yesterday I start up the truck and let it idle while I brush off the snow (there is a new bylaw here, and you are not allowed to idle anymore unless you are in the vehicle or brushing it off). It was about 5:20 in the evening and dark out. The automatic lights were on, everything was working fine when I started it.

After I was finished brushing the snow off, I got back in and drove off. After about two or three minutes, the dash lights go out. All of them. The headlights went off, also. I manually turned the headlights on (the dash lights stay out) and when I stopped to check everything, I noticed that while the headlights were coming on manually, the tail lights did not come on at all. Signals, brakes, and flashers work fine. Dome lights all work fine and normally including when using the dimmer switch.

I checked the manual and pulled the passenger compartment fuses and visually inspected them all, they all checked out.

All the indicators in the dash work (MIL, Brake (!), Speed Cont, Check Gage, etc), but go out when I turn on the headlights. The actual bulbs behind the dash do not come on at all, ever. For example, if I press the O/D OFF button, the indicator will come on only if the headlight switch is off. However, the O/D will still turn on and off because I can feel it. The only indicators that come on are the ones that do not dim using the dimmer switch (MIL, turn signal, and highbeams).

The little green light on the automatic mirror is on to show that it is night and the lights are on (though they are not).

This morning I disconnected the battery and checked the power distribution box and pulled Fuse 11 (15 amp I believe). It was blown, so I replaced it and now everything works fine.

During all this I noticed that my left brake light (only the brake; the tail light works fine) is burnt out, but I don't know if that is related or just a coincidence. (EDIT: I replaced the brake light and it's all working so far...)

So I keeping an eye on it now. Funny thing is that I just did a bulb-to-LED conversion a couple weeks ago, so I thought that might have something to do with it... All the LEDs I installed work fine.

Hopefully that helps someone out down the road.

 

[budwich]

Most likely cause is that your dimmer module lost an output of which there are two.... or the voltage in on that side is gone (ie. fuse, wire).

 

[Cobraguy]

Boy...this circuit is confusing at best! But for the life of me budwich, I can't see where the dimmer module (you are talking about the dimmer control switch on the dash that controls brightness, right?) comes into play here where the autolamps are involved too. Here's my thoughts. Please keep in mind I'm using 1999 schematics...not 1998. First, check all fuses...especially #'s 11 and 36 in the interior fuse box. The OD light indicator gets it's power from the headlight switch. So you should be seeing the same behavior from the 4WD and Cruise indicators as they are all on the same feed. The power to the headlight switch for this circuit comes from the dimmer relay that's located in the relay box behind the dash.

Now it gets interesting. If you lose the output signal from the Autolamp sensor in your mirror, you can still get the green LED indicator lamp on the mirror that shows it's on. However, you then lose the signals to the park lamp relay, the headlamp relay, and the dimmer relay. None of these will work. By turning on the headlight switch manually, you energize the headlamp and park light relays...but not the dimmer relay...so no instrument lights with manual light control. See the common factor? It's the dimmer relay. If your fuses are good, I would look at that relay and check the signal from the autolamp sensor.

 

[budwich]

Autolamps only turn stuff on/off...it don't dim. The circuit diagrams are fun to follow cause of the "onthis page" stuff making tracing difficult...but the dimmer is involved and the connection is relatively straight forward from the module to the light albeit thru a "massive" splice. If the output is there at the module (note this IS NOT 12vDC), then the next place to check is a broken splice as mentioned.

 

[Cobraguy]

not sure what you mean by the autolamp not dimming...that's certainly a given. But it does have something to do with the dimmer relay in the relay box. Could be a broken splice...but there should be other issues if true. Tough one to find...but should be straight forward diagnosis.

And believe it or not, the RAP module is involved in this circuit. It too receives the autolamp module output.

 

[muskegolake]

I replaced fuse #11 in the Power Distribution Box under the hood and... VOILA!!! Dashboard lights!!!

 

[ornithology]

Check your owners manual and use process of elimination to take figure out what fuse it is. They should have a diagram in there.

 

[Frazil]

Boy...this circuit is confusing at best! But for the life of me budwich, I can't see where the dimmer module (you are talking about the dimmer control switch on the dash that controls brightness, right?) comes into play here where the autolamps are involved too. Here's my thoughts. Please keep in mind I'm using 1999 schematics...not 1998. First, check all fuses...especially #'s 11 and 36 in the interior fuse box. The OD light indicator gets it's power from the headlight switch. So you should be seeing the same behavior from the 4WD and Cruise indicators as they are all on the same feed. The power to the headlight switch for this circuit comes from the dimmer relay that's located in the relay box behind the dash.

Now it gets interesting. If you lose the output signal from the Autolamp sensor in your mirror, you can still get the green LED indicator lamp on the mirror that shows it's on. However, you then lose the signals to the park lamp relay, the headlamp relay, and the dimmer relay. None of these will work. By turning on the headlight switch manually, you energize the headlamp and park light relays...but not the dimmer relay...so no instrument lights with manual light control. See the common factor? It's the dimmer relay. If your fuses are good, I would look at that relay and check the signal from the autolamp sensor.

would unplugging the mirror help fix the problem? Are there common problems associated with the mirrorand auto lamp thing?