Electrical demon! help appreciated

[mattcrp1]

Originally Posted by 68c10airstream

As a past ASE master mechanic of 30 plus years go over every ground on the truck (the forgotten circuit). I know 67-72 grounds well and I suspect your body style to be close. Remove every ground that you can find, shine up the eyelets and bolts and remove paint from the surface and reinstall,. Start at the block, Rh inner fender to frame??, valve cover(s) braided straps to firewall, and possibly frame rail to box??. The most important connections are at the battery. If your battery clamps have 2 bolts pinching the cable to the clamp throw your battery cables away and buy good brand usa made cables (standard motor products) that have molded ends. What I mean by this is the cable insulation is molded into the lead battery clamp. Air shouldn't be able to get at the copper strands inside the cable. I could fill a dumpster the number of cables I have thrown away from the TEMPORARY EMERGENCY BATTERY CLAMPS THAT USE 2 BOLTS TO PINCH THE CABLE after you strip the insulation. They are temporary use to get you by until proper replacement. Enough of my rant but electrical and drivability problems were my specialty, Good luck, Brian F.

This sounds like the area you need to look. A voltage drop test will tell you for sure, sounds like battery cables.