12 Volt Issue

[evanconklin]

What I have:
'73 Overlander
Progressive Dynamics 4060: 60 AMP Converter + AC/DC Distribution Panel (all fuses checked and good)
No Battery
15 Amp 120v shorepower
1-Way Fantastic Roof Vent (fuse checked and good)
Checked ground wires, all are secure and running through the shore-power ground.

My Issue:
Whenever I try to turn on my Fantastic Fan, all current on my 12 Volt line drops. I'm spliced into the existing blue, roof-vent line. When I have the Fantastic turned to off, there's current on the line. The converter/distribution panel is working because I have a car amp on a separate line that's powering my speakers and they're still working. The current on my Multimeter ( set toDC 20) reads .62 (but jumps around a bit) when there is current.

What could be causing the voltage to drop to zero when I turn the vent on?

[TG Twinkie]

Bad connections. Either on the common/ground side or the fuse holders. Check to see of the fuses are clean and tight at the connection point. Check the connections at each fuse and where the converter connects to the DC buss.

[HowieE]

In a DC circuit voltage only goes to zero on the ground side of a load. You can reduce voltage on the source side of a load if you have another load in parallel with that load but that will only be a small drop.

If turning the fan on drops the voltage elsewhere in the trailer I would assume the fan is not turning and may have a shorted motor. If you are saying the fan runs but the voltage drops elsewhere in the trailer I would look for a near open wire before where ever you are reading that zero voltage. A poor connection could have you seeing voltage on that point while there is not load on the circuit but when loaded that section. of the circuit might be effected