Gauges work, then quit.

Hi guys. On my 5 ton dump Cummings engine ever since I have owned it about 2 years now all the gauges work for the first minute then all the electric gauges stop registering. it happens consistantly one min after start up, volt meter drops to 0, fuel goes to empty, temp to 0 etc. I had assumed it had to do with the bad alternator I had, but I just put in a brand new alt. not original but the guys at the shop said it was equivalent and the issue persists, Any thoughts? I dont know much about the wiring on these rigs, so if you know of a relay or something I should check a location would be helpful .

Thanks for any help!

Lucas

Power control box. All gauge power comes from it. I have rebuilt boxes available in the parts classifieds

Yep, like Simp states, the PCB. Give it a percussion adjustment, but that will be temporary fix. Get a spare and rebuild your original. Easy pesy....