Did you clean the ground on the block? You are losing the connection to the battery. It's either a bad connection or a bad cable. Maybe do a voltage drop to check the cables.

 

I did clean the connection at the block but had not thought about cable(s) being bad-- will check that out--thanks for input

 

Thanks stepman- you were correct- changed out the positive battery cable and that fixed it. sorry it took me a couple of days to get back to you but my internet went down Tuesday and AT&T just got it back up tonite.

Thanks to everyone for your interest and assistance.

 

Good to hear.