Voltage completely drops when switch turned to on - No start, no gauges

[Ozshadow]

1999 270 Sundancer with the 7.4. I went to start it for the first time this year and got nothing at the helm after the first try. The first time just turning the key on I heard several clicks without turning it past run. I turned it off and back on then went to start it and nothing.

I have clean tight battery connections, fully charged. The trim rams and tabs all work just fine.

I disassembled the dash, and found 12+ volts at the breaker and B connection on the switch. When the switch is turned to run, voltage drops below 1v to something like 0.18v, no beeps, no gauges move.

At the engine I could not measure any power at the 50amp breaker on either lug.

What could be happening? Something appears to be shorting the circuit when turned to the run position without tripping any breakers.

Thoughts?

 

[Ozshadow]

May have just found the issue. Reach down the main 12v cable tracing it to the starter. At the fuse it's just flopping - feels like a bolt is backing out. Time to go dive deep and see.

 

[alldodge]

You have corrosion, start at the battery cables then where they connect on starter and block. Don't by pass the block connections, remove, clean and reinstall

 

[Rick Stephens]

Start brushing. Cable eyes, studs, connectors. All need to be bright and shiny.

 

[Ozshadow]

SOLVED - main battery cable loosened at the starter solenoid. Had backed off about 1/8" or so. Surprised I did not have problems last year but also happy I caught it before it became a huge explosion or left us being towed in.