HVAC Backlighting Issues (Not a Burned out bulb)

Hey guys,

I'm having a hell of a time figuring out why some of the backlighting is non-operational in my '05 Tacoma. Initially, I noticed the HVAC backling was out and got new bulbs, but that didn't work. Then I checked all my fuses and they seem to be good as well. I'm not sure what else it could be. I also have an '09 Tacoma so I tried swapping the HVAC control units. Both units light up in the '09 but neither one lights up in the '05. Addionally, the backlighting for the fog light switch and the Rear Dif lock switch are also out. Anybody have any idea what might be causing this issue?

Any help would be appreciated.

Thanks.

 

Did you check all the fuses in the engine bay also?

 

I checked all of the standard (type A) fuses in the engine bay, but not the larger square fuses there.

 

probably its going to be the dimmer switch (if seen it happen)

thats if the other lights dont light up (not counting the instrument cluster)

 

Yup, I'll bet the stereo backlighting is out as well as the switches and the HVAC controls. These trucks have a dual pole dimmer rheostat, so the dash cluster is on a separate curcuit within the dimmer.

 

Well, I replaced the stock radio with an aftermarket head-unit so I don't know if the backlighting is out there too. If it is the dimmer switch, is the fix as easy as just getting another one and swapping it or is it a more involved process that I might want to have a professional do?

 

UPDATE:

So I took the Rheostat/dimmer switch out of my '09 (which I know works properly) and tried it in the '05 and the backlighting in the HVAC, etc is still not working...

 

I would start checking voltage at the connectors and work your way back.

Easier said then done of course.

 

Huh. Another question then. Do all your park / tail /license plate lights work as they should?

 

Yeah, all the other lights are working fine it's only the HVAC and the fog light switch that aren't illuminating.

 

I had the same issue on my 2014. I blew something. Replaced the Dimmer Rheostat with a new one (found cheapest on line for about $100, just under actually) and it fixed everything and part of the AC HU lighting. By this I mean they are on and VERY dim but show up in the dark. all of my dash lighting was out, to include the instrument cluster. The AC HU lighting is not bright like the rest of the ambient lighting but you can see it. If you need the link let me know. I think they are the same part number. Toyota seems to use the same dimmer in a few vehicles.

 

Was this issue ever solved? I'm having the same problem with my 09.