**** Happy Birthday *****
Agree with Jerry on the 6V vs 12V light switch. Unfortunately it does not eliminate a possible over-current causing the bi-metallic 12V switch to open.
A shot in the dark here. Clrh2ofrank, when you converted your truck to 12V, did you happen to add relays to switch on your head lights?
Your statement:
Took the poitive cable loose from the battery and put a volt meter between the cable and the post. got 12+ volts with the everything off.
If everything is turned off, you pulled off the positive terminal cable and measured 12V between the cable and positive battery post then my poor brain says you should have read 0 volts. If you read any voltage at all then there has to be current flow through your meter. This means something is still connected or using power. You didn't mention anything about problems with your battery draining and having to recharge it.
