Cluster lights

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Rome03

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Ran into an issue with my cluster lights and I’m scratching my head at it.

Couple of the cluster lights had died, so I figured I’d get the LEDs to replace em and brighten it up. Pulled all the old bulbs, replaced em with LEDs, and no lights in the cluster works m. All the actual gauges work fine, but the backlight bulbs don’t.

Okay fine, I pulled the LEDs out and put the the standard bulbs back in place. Still don’t work.

I don’t know that it’s the circuit board on the back, bc they were working before all this mess. I’ll run a test light to the back later today to confirm. Oh and I guess I should mention my interior dome light and headlights all work just fine.

Am I missing something super obvious here? That’s what it feels like.
 

Sad Sack

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Fuse?
 

legopnuematic

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Give the headlight switch a twist back and forth to see if they come on? Sometimes the rheostats get a little crusty and don’t make connection reliably.
 

Rome03

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Give the headlight switch a twist back and forth to see if they come on? Sometimes the rheostats get a little crusty and don’t make connection reliably.
Did that. No joy.

The circuit paper on the back is pretty brittle so I’m assuming it’s that. Just weird that it was working before and not now.

The big plug that goes in the back is what powers everything, right? And if my turn signals and such work but not my backlights for the cluster…stands to reason the circuit paper in the back has a broken connection.

I don’t even know if that’s something I can troubleshoot with a test light?

EDIT: this certainly feels like a bad ground to the backlights in the cluster. As far as I know the printed circuit in the back is how it grounds. Can anyone confirm this?
 

legopnuematic

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Yes the plug is what feeds the cluster for everything.

There should be three grounds (black wires) in the cluster connector, these are all spiced together upstream in the harness.

The power feed for illumination is a grey wire. Do the wiper switch and hvac controls light up still or?

Wiring manuals here if you don’t already have one for your truck.
 

Rome03

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Yes the plug is what feeds the cluster for everything.

There should be three grounds (black wires) in the cluster connector, these are all spiced together upstream in the harness.

The power feed for illumination is a grey wire. Do the wiper switch and hvac controls light up still or?

Wiring manuals here if you don’t already have one for your truck.
Yeah the backlights for hvac and such light up.
 

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