Docktergreg
Registered User
I was trying to diagnose the winch on my 1992 f350. Since I only have 2 hands, I used a jumper wire with alligator clips to connect the ground lead from the multimeter to ground on the winch. To my amazement, the voltage went up from 12.77v to 12.89v. So I went straight back to + & - on the battery posts with the probes and got 12.77v. I ran the jumper to the - probe again and got 12.89v again. Now really confused, I kept the jumper hooked to the - lead reading 12.77v, then touched it to the - battery post, and it dropped to 12.77v, and back to 12.89 when I pulled the lead away from the post. How is it possible read more voltage than the battery has using the jumper wire in series with the lead than without it?
