Cluster and Air Lights Issue

I apologize if this is covered elsewhere. I’ve googled and googled but to no avail. Seen lots of semi related threads, but nothing that really spelled it out for me.

2008 Tacoma 4L V6 4x4 Manual Tran

Issue:
1) Speedometer, tachometer, odometer, fuel and temp gauges don’t function.
2) Backlights for cluster don’t work.
3) Backlights for the three air dials don’t work.
*All other lights seem to be functioning.
*All accessories seem to be functioning.

All was fine when I drove home from work. The next morning none of these items worked and after 4 weeks, no signs of life. Checked all fuses and they are good. Pulled the dash apart and everything is still plugged in.

She is just shy of 300k miles. Maybe she’s finally getting broken in.

Any help would be appreciated.

 

Do your tail lights work?

 

Is the dimmer switch turned down

 

Dimmer switch has been turned up, down, up and down again. Unfortunately, this time it won’t be that easy.

Tail lights are also working. Just the gauges and backlights in the cluster and at the air controls.

Perhaps it just wasn’t meant to be. Can’t go above the speed limit in this LA traffic, so maybe I don’t need these options anyways.

 

The illumination stuff at the cluster and hvac panel all goes through the same circuit, usually the dimmer switch I think. The switch itself could be open circuit

Are you sure you didn't miss a fuse? Behind the dash? Under the hood?

Any crispy/melted connectors behind the cluster or dimmer switch?

I'd be looking for a place where the gauge power and the illumination power is shared.

One of these guys should have a schematic

@Dm93
@Jimmyh

 

There is one.
It’s the J4 connection.
I’m looking for it’s location now.

 

Here's the diagrams for the instrument panel and illumination circuit.
I can't really see anything that would affect the gauges and only part of the illumination circuit.

 

J4 pin #12 is power from tail fuse.
It’s common to both the A/C Lights and Cluster.

I’m not saying that is the problem.
But it’s a start, since the tail fuse is good?

 

Is "IG 1" (10 amp) and "IG 1 2" the same fuse? Drivers side junction box..

One goes to the rheostat, one goes to the combo meter

 

No they are different fuses.

The more I think about it, more I am wondering why the gauges don’t work?
If they don’t work, I doubt it is related to the J4 connector.

 

He might have 2 different problems

 

2 separate fuses and they power much more than the cluster and illumination.

 

From previous post, I recall that if you the unplug the rheostat, the gauges go full bright.
Does that help? No, not really. But it’s easy enough to do. If gauges work. There’s the problem.

My problem is not understanding why the speedometer and tach don’t work.
At least looking at diagrams, I can’t tell. I’d have to start poking things. Lol

 

Gauge illumination is NOT tied to gauge functions...
Dash Illumination is, so is the tail circuit and towing tail circuit.

 

Yes sir. Thanks Caribe

We may be dealing with multiple issues?

 

Update:
Dismantled the dash and pulled the cluster and the air controls. Didn’t see any obvious melted or burned wiring anywhere. Gave it all a good dusting and reassembled. Good news - the lights on the air controls are back on. Maybe just a loose connection? I can confirm now that the dimming switch does work as it does dim and brighten these lights. However, the cluster gauges and backlights are still a no go. All the individual lights in the dash (ie. check engine, headlights, etc.) all seem to work.

with the busy holiday weekend I didn’t get a chance to read all the helpful comments in detail. I’ll reread them all again this week and dive back in there this weekend. Thanks for the help.