ok, so i started up the ole dak and headed off to the gas station and all is normal. i fill the tank (21.67 gallons, cuttin her close!) i went into pay, came out and started her up. the "check guages" light came on and my battery guage read zero. wtf? so i drove it home and shut it down. restarted it and all is back to normal. i then took a drive and 2min into it the guage again dropped to zero but the truck ran fine. as well as the blower and the radio and all other accesories. ok, so now what is the problem? with the guage at zero, i read 14.4 volts at the battery with my V.O.M. , and 12.7 at the battery when its not running. i have not been able to get to autozone for a charging system check yet, but i dont think that is my problem. could it be my ctm? does the cluster get controlled by the ctm. im taking it to work in a bit and i hope i make it with no issues. anyone have any ideas on the matter? thanks for the help!!

 

I don't think it's your charging system since if you really did have 0v your truck wouldn't keep running. Besides, you've verified the gauge is wrong.

Did any other gauge act up?

The cluster is a computer in itself. Try a cluster diagnostic test.

Key off. Press in the trip reset and turn the key on while holding. Continue holding about 10 seconds until CHEC shows in the odometer. It'll sweep all the gauges and test all the lights. If there is a fault it will display a code starting with 9xx. These are not the same as OBD "P" Codes.

The wiring diagram and the Factory Manual disagree on the gauge. One chapter says that it runs on the PCI bus and is computer controlled. Data comes from the PCM. The other shows it wired as a conventional analog meter would. But, the CEL for low/high voltage is controlled by the PCM.

Can you pull the CEL code? Do the key dance.

At a minimum, check all battery connections.