Need some more help, as i go down the road the oil and temp guages are fine when I turn on the headlights they both peg to the right, If i turn off the headlights these two gaugs go back to normal ???Help.

 

Apparently there's a short somewhere that's allowing the guages to find ground through the headlight circuit.

 

Had the same issue, my ground was attached to the steering column cover. I don't know if that was the stock location for the ground of not but it wasn't ground for crap there. I routed it to the frame and everything went to normal.

 

I spent two days reading post on instrument cluster acting funning and made a game plan. I went to the yard and pulled two metal straps off of a Bronco and a F150 that were screwed to the hood and the fire wall, I believe these are factory ground straps. I also pulled a fire wall to engine factory ground strap the longest I could find about 16" or so. Spent the whole day doing the following removed my fire wall to engine ground strap and cleaned the end and bolt, cleaned the fire wall area and bolt hole on the block and reinstalled. Cleaned the negative battery ground at the engine block and attached at the same place another ground wire to the frame. Then installed the two hood ground from the back of th cab to the frame and the other to the bed to the frame Guess what all gauges work great. the altenator used to move a little while driving a little sometimes when I would signal, it know stays steady to the charge side a tad, the oil and temp gauge run smooth, the oil runs about R on normal and the temp runs on the O on normal, even the fuel gauge seems strong and steady, when I turn on the head lights nothing pegs to the right, its all about grounds, dont know which one or if all did it but its great. Went for a drive this evening and all was wonderful, hope it stays that way. Thanks, all you ground boys. OEM78