by bgsengine » Tue Jul 14, 2020 11:23 am
Voltage drop test - has been discussed several times within these forums.. basically take your DVOM, put one probe on engine block (bare ground) and the other probe on Battery negative terminal - and crank engine over - If you see more than a tenth (0.1) of a volt either way (+ or -) maximum of 0.5V , then you have a resistance in the ground circuit (the reading on your meter is how much voltage is being lost - DROPPED - by the high resistance) if you do find high resistance, use the same probe technique from the next ground point (bare ground on frame or engine mounting surface to the battery negative terminal where it bolts to frame.. then from battery ground mounting at frame, to battery negative terminal on B- post, etc - until you see no voltage drop - that'll localize the resistance to the place you had probes connected previously) Same can be done on positive side (B+ to Starter + post and work back through the circuit)
The key is to be checking for stray voltage values while the circuit is under load..
How poor are they who have not patience. What wound did ever heal, but by degrees? - Iago (Othello Act II, Scene 3)