We have a newly acquired 2000 Dodge Ram 1500 Ex Cab with the 5.2 engine. We knew it needed some work when my son bought it cheap (brakes, parking brake, ball joints, track bar, front wheel bearings), alternator and have accomplished all of that. The are hopefully only two issues left, the main one being the dashboard voltage meter keeps dropping to around 8 volts or lower. We check the battery with a multi meter and it is still shows a full charge. Turn the truck off and on again and the volt meter is back to 12. He did tell me that when he installed his radio he put the cable on the battery wrong and blew some fuses but has replace them all. We put in a rebuilt alternator and had the battery tested at two different auto places and it tested fine. The second minor issue is squeaking from one of the pulleys for the serpentine belt, we've already replaced the adjuster pulley, of course the alternator and the pulley that sits to the right of the alternator which has lessened it but there is still a squeak. Is this common in these trucks?
Thanks a bunch and hope to hear some great ideas of finally getting this boy on the road

 

Volt gauge gets it's cue from the PCM as what it is supposed to show.... (a rather convoluted path at that.....) Thing to do would be to test the charging system when the gauge is showing low voltage, and see what is actually happening. Might just be a bad gauge.

As for the squeaking, take off the belt, and spin the pulleys by hand. See if anything feels wrong. Also, when you replaced the adjuster pulley, did you JUST replace the pulley, or did you replace the entire tensioner?

 

Make sure you have reattached all the grounds. There are several on the battery, including to engine block, fender, and frame. Also around the alternator and firewall.

 

+1 on the ground at the alt.

 

To HeyYou, gdstock and gertie240
Thank you for all your input, we beleive we found the cause of it. There is a 140A fuse in the engine fuse box that connects between the positive and negative cables coming into the fuse box, the positive side tested fine but the negative did not, we replaced the fuse and volia no more issue. Initially we had thought as everyone else to check those other things.

As for the squeaking we only replace the pulley on the tensioner. So as of this point we have a replace pulley, a replaced pulley on the tensioner, a new water pump and a new alternator. by ear it sounds like it may be coming from the middle of the engine which is leading me to believe possible fan or maybe crankshaft pulley

 

Check that the tensioner is actually putting tension on the belt. If it isn't doing its job properly, the belt can slip, and that will give you a nice squeak/squeal.

 

So I checked the tensioner and that was fine, had proper amount of pull on the belt, eliminated the crankshaft pulley buy removing the belt and starting for a couple of seconds (no noise). I made note of when I took the belt off and reversed its position so that the portion that was facing the front of the vehicle is now facing the engine and low and behold the squealing is gone. Just found I've got no backup lights, brake and tail lights are fine so I'm going to be testing the neutral safety switch.

Thanks everyone for your help and input.