more on electrical

[55 50 Ron]

Been working on a Farmall "H" that wasn't charging. 6 volt positive ground system. Got it charging normal again and while working on it I ran across a condition that puzzles me. During some testing, I had the cover off the new 4 terminal voltage regulator and noticed sparking of the regulator contacts (when manually activated) WHEN the chassis to positive battery post cable was disconnected !!!

My puzzle is where would that sparking current be coming from when that cable is not connected? It seems that there must be a "hidden" chassis path somewhere as the regulator should be totally dead with the bat cable open..

All you electrical gurus chime in as I would like to figure this out.

Additional info is the battery is new. I've cleaned all the paint, rust and greasy dirt off all contact areas on generator, regulator and mounting to engine block. The generator motored and slowed with control of the field and was polarized BAT to ARM. Has steady charge current on ammeter when field is connected to generator chassis.

It's working and totally usable but I'm still puzzled.

Thanks for any theory comments. I hope this is not something my old brain should know but has forgotten.

Thanks for your comments.

Ron

 

[da.bees]

Are you saying regulator sparks while engine is running and chassis to positive cable is disconnected? Look at this way. If engine will stay running once started then battery is removed (it should) ,the genny must be making current and that current must have a positive and a negative field else coil couldn't supply spark. Perfectly normal. For your peace of mind put volt meter between positive post and disconnected positive cable while tractor IS NOT running. If you detect any voltage something is wrong,if not there's nothing to worry about.

 

[rustred]

Been working on a Farmall "H" that wasn't charging. 6 volt positive ground system. Got it charging normal again and while working on it I ran across a condition that puzzles me. During some testing, I had the cover off the new 4 terminal voltage regulator and noticed sparking of the regulator contacts (when manually activated) WHEN the chassis to positive battery post cable was disconnected !!!

My puzzle is where would that sparking current be coming from when that cable is not connected? It seems that there must be a "hidden" chassis path somewhere as the regulator should be totally dead with the bat cable open..

All you electrical gurus chime in as I would like to figure this out.

Additional info is the battery is new. I've cleaned all the paint, rust and greasy dirt off all contact areas on generator, regulator and mounting to engine block. The generator motored and slowed with control of the field and was polarized BAT to ARM. Has steady charge current on ammeter when field is connected to generator chassis.

It's working and totally usable but I'm still puzzled.

Thanks for any theory comments. I hope this is not something my old brain should know but has forgotten.

Thanks for your comments.

Ron

Your generator is producing current which is normal for it when the battery is disconnected. Nothing to do with the cables. The power is going to the starter solenoid terminal where the battery is hooked to. You can hold a generator up to a wire wheel and add spin it to make it produce current. It’s not like an alternator that needs a bit of a kick of current too. I am no electrical guru ! I would say it’s the vibration of the contacts that is producing the sparking. I have seen that many times also. If the amp gauge is not jumping around it’s all good. Amp gauge jumping means the contacts in reg are dirty.
get it charging.

 

[55 50 Ron]

I wasn't clear as I forgot to say that the engine WAS NOT running when I was seeing the sparks at voltage regulator contacts. That's why I was puzzled.

I'll use da.bees suggestion of "using a voltmeter" and post back later.

Thanks for your comments. Ron