Welp, shorted out the gauge lights. Fuse OK.

[tangouniform]

I finally got my gauge cluster w/ factory tach put together and installed when I realized one of the bulbs had burnt out. The light in question is behind the voltmeter, and because I'm lazy and didn't want to remove the gauge to change out the light, I grabbed a pair of needle nose to pull it out. I then put a new bulb in the needle nose, forced it into the socket, and BAM, shorted out all the gauge lights. I'm assuming my pliers touched both sides of the socket :doh:

First thing I checked was the fuse for the gauge lights, and it was fine. The tail lights work as well so I know it's not the fuse. I then checked the gauge light bulbs, and all of them are fine. So I then pulled the cluster back out to check the ribbon/circuit board on the back, and everything looks normal. I traced the ribbon for the lights back to pin #2 on the harness, so I checked for voltage at pin #2 with the headlights on, but nothing. I'm assuming this should show 12v with the lights on.

So the fuse is good, the bulbs are good, the ribbon appears ok, but there is no power at the harness. The only thing left would be the headlight switch, correct? I'm just baffled how grounding out a light socket wouldn't pop a fuse or a bulb, but instead fry something else. Anything else I'm maybe not thinking of?

 

[mechted]

Check the fusable link on the firewall. I replaced mine a long time ago with a 30A fuse, when I short something inside the cab, that is usually what blows for some reason.

 

[tangouniform]

I have power at the harness/connector at the cluster, but still no lights. I even plugged in another cluster with different lights and still no luck. I'm very confused.

If I have 12v at the #2 pin on the connector when the light switch is pulled, how could I have 0v on 2 different clusters? I'm not too familiar with these ribbon board type of circuits, but shouldn't I be able to just place one of my leads on the ribbon itself to test power? Or is there a film over it to where my test lead wouldn't be able to read the voltage? I'm just confused how I can have 12v at the connector but 0v on the ribbon.

How does the cluster ground? Am I missing something obvious here?

 

[diesel4me]

There should be a black ground wire that grounds the dash and headlight switch...its hard to find,up near the E-brake mechanism..
But I'd think a fuse or fusible link would fry long before a wire would fail,and you'd have seen smoke and smelled it too..

Did you check the fuse marked "LPS" ?..thats is for the dash cluster lights,the "gauges" fuse is separate on some years..

 

[tangouniform]

I got it all working. Turns out the pin on the connector wasn't making contact with the circuit on the cluster. It was slightly recessed and that was enough to prevent contact. I pried it out and it's working now. It's always some minor detail.