HVAC panel electrical circuit

My HVAC panel (with three knobs, right under the radio) light is out. Which electrical circuit is that?

 

If you are referring to the backlighting it is powered by the TAIL Fuse (10A) in the interior fuse box and variable ground is provided through the Rheostat knob for dimming.

 

I am referring to the light that makes the knobs visible in the dark. They work, only that you can't see them.

 

That would be the backlighting/illumination, diagrams posted above.

 

do you think just replacing the 10A fuse will do or I need a whole tail lamp relay?

 

Are your tail lights working? If they are then there's nothing wrong with the TAIL Fuse and more likely either the bulbs are burned out in the A/C panel or there's an internal problem with it.

 

Yes. It is odd that those knob lights would be on the same circuit as the tail lights

 

Could also be a failed rheostat judging by that diagram.

 

Not at all. Dashboard backlighting is typically powered when you turn the park / tail lights on.

 

Not really, alot of vehicles have the dimmer circuit powered off the tail lights.

True, my other question would be are all the other backlights working.

 

what is that?

 

But if the radio and switch backlighting works then it’s not the rheostat.

 

yes, all the other ones are fine (like the main dashboard)

 

could it be the same root cause as this: https://www.tacomaworld.com/threads/fan-blowing-only-when-on-high.433412/#post-28259384 ?

 

This may be helpful:

https://www.tacomaworld.com/threads/heater-control-light-bulbs-an-alternative-to-dealer-gouging.189371/

Oddly enough, I only ever used the first two of that pack of bulbs before my Taco was killed.

 

Then you will need to pull the A/C panel and check the bulbs.

No those are separate circuits.

 

do you think for the fan blowing problem it is almost certainly the blower resistor? I am trying to fill my basket at RockAuto

 

Pretty likely considering they fail alot bet there's always a chance it's something else, many times the plug melts too that's why there's an updated resistor and harness:

Resistor: 87138-04070
Connector: 82141-04Q80

The wire colors on the updated connector are slightly different as shown below.

 

Does your fan work on High Speed?

And I see your truck is an 07’
So is mine. 2 of the 3 bulbs for the A/C controls have went out. They are easy to replace. It literally just pulls out from from the bottom. GET GOOD NAME BRAND BULBS. No name aftermarket ones fit loose. The will rattle loose within a couple weeks.