Ford CMP (Flathead V8) ammeter wagging back and forth

[Lauren Child]

My CMP has started wagging it's ammeter needle rhythmically back and forth as I rev the engine. It operates fine at low revs but as they increase it starts happening.

 

I seem to remember this means something (overload?) but I can't find the reference in any of the books I'm picking up.

 

Can anyone clue me in?

[Big ray]

I believe that its overcharging, and needs the regulator setting.

[wally dugan]

HI LAUREN

 

If I remember right ammeter needle flickers

1 inter mittent short circuit or open circuit between dynamo cut out and switchboard

2 internal fault in dynamo

3 fault in cut out

 

I HOPE THIS HELPS

 

REGARDS WALLY

[Lauren Child]

Thanks chaps, I'll do some more tinkering.