Intermittent Discharge

[JohnB]

70 W200 318
I took my truck out for a highway ride yesterday about 100 miles round trip. After driving a bit {55 mph}, I noticed the amp gauge was in the discharge area. I turned off the heater and headlights {cold and foggy morning} and the gauge still showed a slight discharge but was better. After driving a while, the gauge suddenly jumped a lot to a indicated charge and settled to a normal charge reading after about 10 miles. Repeated this behavior after a few more miles, discharge....then charge. On the way home, the issue finally stopped and gauge showed a slight charge and was in the area it has always been for the remainder of the trip. I was thinking a bad ground but I purposely drove over some bumps to see if it would change and it didn't. Could this be a failing VR {original Mopar VR dated 1970}? Any other suggestions appreciated.
John

[PwrWgnDrvr]

Failing VR, alternator or a bad connection somewhere.

[JohnB]

Failing VR, alternator or a bad connection somewhere.

Terry,
I suspected a bad connection or VR failing but can an alternator be intermittent? I thought that it either works or it doesn't?

[PwrWgnDrvr]

Yes John, it is possible for an alt to be intermittent, altho that is uncommon. I would start with connections and the VR.

[hmaynord]

I would start with connections ....

especially the bulkhead if it has those

[Roxyflash]

Check the plug going into cab probably starting to melt