This is weird. Well, maybe not that weird. I've been customizing my gauges for a while. I'll put up some pics when I'm done but it's not really relevant.

Anyway, I was troubleshooting some issues with the some of my backlight bulbs and I did some things I probably shouldn't have:
Plugging the cluster in without the face/needle panel connected. Hot-plugging the cluster. Etc.
After getting all that working, suddenly, my gauges stay on when the truck is off and the key is out. Fuel, battery, temp and oil pressure all maintain their position when the power is off. I gave the needles a little push toward 0 and they bound right back up to live information. I can put gas in and watch the needle climb while the truck is supposed to be off. Speedo and Tac have adopted no such attitude and the Odom display turns out like it should. What I break??

I have a second cluster that I was pulling parts from for modifications and the modifications were completed long before this happened. Anyone know what I broke and will I maintain my Odom reading if I just use the board from the donor cluster?

I guess you could call this one of those "Is it a BUG or a FEATURE?" situations.

 

You hooked into a Battery power always on somehow. and without knowing what exactly what you did I'm afraid you won't get a quick answer to a fix. Do you know where the link is posted to the Factory Service Manuals are in the other threads? they have all the wiring diagrams you'll need to correct your problem.

 

No wiring was changed. The face plate was changed, the backlights were changed to LEDs, needles were painted and I installed a clock where the PRND21 gauge would go (this is a 5spd Dak). All of that worked out great. Clock power, illumination and ground were soldered to the circuit board where the PRND21 gauge would've been soldered. Looks great. Works fine. Suddenly today, my gauges have power when they shouldn't. And there's no technical manual available to the public that will help me diagnose the clusters' circuit board. Turn the key on they drop to 0 and then go back to where they belong. I doubt the gauges pull enough power to cause battery trouble. It's just..weird quirk all the sudden.

 

No I don't mean you have battery trouble. but somehow your gages have ALWAYS on battery power that has suddenly appeared

" I installed a clock where the PRND21 gauge would go (this is a 5spd Dak). All of that worked out great. Clock power, illumination and ground illumination and ground were soldered to the circuit board where the PRND21 gauge would've been soldered."
the manuals will be a huge help> it"ll give you a base of what you should have

somehow battery always on power is either supplied or is bleeding through to your gages

 

electricity you got to love it> i think the factory service manual will be of help>

 

While I was in the middle of posting this I was desoldering the clock to see if that really was the problem. It's still doing it, though now that the truck has cooled off a lot, I've noticed they don't jump to accurate.. They jump about half way. There's a bleeding short in the board somewhere and I don't care to fix it. Does the Odometer follow the gauge cluster or the computer? I'm just going to put the other board in and reinstall the clock. :/

 

One thing you can count on is that the auto industry will use the cheapest components it can find. I think you might have a thermal component failure on one of the boards. It may read OK when cool but heat it up might cause it to semi-fail. I would also ck any obvious Capacitors to see if they are shorted, however, I suspect it is a thermal break down. You can ck the board by heating it with a hair drier then cking your readings against the board when it was at room temperature

 

I'm wondering if you delaminated/internally shorted a part of the PCB or something installing the clock.

Mileage goes with the cluster I believe, but you can swap them to at least test the theory.

 

That's a beautiful schematic. Doesn't explain much, though. Just pwr/gnd.

Edit:Edit:Edit:Edit: UGH! Once I undeadify my phone I'll post the video I took.

 

Video

You know, you can find a lot of Google hits for gauges NOT working, but absolutely nothing about gauges working when they're supposed to be off.