Dashlights stopped working after service.

2017 Tacoma TRD OFF ROAD, double cab, long bed.

I had great, very bright dashlights, with day lighting during the day with no headlights on. Now it is either totally dark without headlights or with very dim night lighting when the headlights are on. The dimmer switch won't go up high enough and ,yes, I tried putting on the day light mode with the lights on. Didn't work. I did have a tail light go out on a cheap aftermarket tail light that has a camper light spliced into it, put in 5 years ago. Could that be the problem? It happened during service. They did an update, AUDIO-0101A7. How can I find out what that does?

 

Wouldn't hurt verifying the fuse.

 

I am not sure which fuse to check.

 

The cab fuse panel has a legend.
Top left fuse (PANEL) 5 amp

 

I did check that and it seemed fine.

 

Does the dimmer have any affect on the brightness?

 

Have you checked the 7.5A Meter fuse?

 

Yes but it only goes up as high as the night lights, which you can't even see in the daylight. The day light brightness has totally disappeared.

 

Where is that located?

 

What is seemed fine? Fuses can sometimes be deceiving. Have you tried putting a new fuse in the slot or putting a multimeter to the old fuse?

 

I will try putting in a new fuse tomorrow. Thanks

 

I don't have a multimeter or know what that is. Guess I will look it up!

 

It's a great tool for narrowing down all problems electrical.

However, if you don't have one, no worries. Swapping fuses will do the same thing, which is making sure, for sure for sure, that the fuse really isn't blown.

I'm not sure how the aftermarket tail light is wired or how it could cross the illumination, but stranger things have happened.

The tricky part is that the dash illumination is wired so that the dimmer (resistor) is on the negative side of the circuit. Usually when things tap into it the opposite occurs, where the dash lights are suddenly 100% bright and won't dim. But again, I can't assume without saying how every aftermarket part is tapped.

 

Passenger side fuse compartment

 

@acugirl see diagram above

 

It's possible. The Panel fuse is powered by the Tail Relay.
And the tail relay feeds the tail light.

This is a situation where I'd like to be there to see/test it myself.

 

Super cool! So I just need to replace the ???fuse? Where is the tail relay? Do I replace that? I am getting the tail light replaced with a new oem one.

 

If the fuse is blown, yes. You need to replace it.
The relay looks like it is non-serviceable. (not removable)

 

That could be it. Splices often corrode and cause problems.