Suspect list: in line order I hope
DEAD BATTERY (And by dead I mean Flat, Does not take a charge at all)
Tripped main DC breaker (usually within 1 foot of battery usually in positive lead)
Battery disconnect switch and/or solenoid
And last but not least all over the chart Ye old bad connection or bad wire.
Start by checking the battery with a TEST LIGHT or better a lOAD test. (Disconnect the negative most lead(s) from the RV before load test. If fail then mark the positive leads with red nail polish or paint or tape before disconneciton and let dry.. in fact do that anyway)
If the battery passes disconnect POSITIVE lead and clean. Disconnect any jumpers and clean Finally clean and re connect negative.
Then if not solved move out with the test light this is way better than a volt meter.
First transfer clip to unpainted frame part and test a battery POSITIVE.. (Unplugged I might add) Bright good. dark bad ground chassis end negative cable.
Then moving the clip as needed (And retesting last good spot to insure good ground) move out along the positive lead any device you find test both power terminals
problem exists between bright and dark
