Question on cut off switch

[MBI Houston]

While driving down the road my ammeter went from a +4 to a minus 1. I looked inside the cutoff switch to see if the contacts were stuck. I discovered that the cutoff switch is a modern diode type. Not being able to decide if the diode was working or not I went to the next logical (in my novice mind) step. I tried to adjust the generator brush. I pushed it into a lower position and there was no change to the ammeter. I then pushed it to a higher position and there was still no change to the ammeter. I am assuming that the ammeter is ok since it shows a minus 8 when I turn on the lights or step on the brakes and then returns to the minus 1. Any thoughts on what my next steps should be? Thanks for you help.

Marshall in Houston

 

[BRENT in 10-uh-C]

How do you know there is a problem? Is there any chance your cut-out switch is also a regulator too (i.e.: Funprojects, etc.)

One quick way to see if the generator is still functional is to remove the belt and using a heavy jumper lead, connect a wire from the starter switch post over to the generator (with the cut-out removed) and see if it will "motor". If it does, then you have a problem elsewhere.

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[Jim/GA]

The next logical step would be to use an ohm meter (or a self-powered test light -- the ones with a little penlight battery and bulb in the handle) to read across the diode to confirm it will flow current in one direction but not in the other. If you can not flow current in at least one direction (toward the battery), the diode is bad.

 

[Geo. H]

My guess is your ammeter reads -1 when it should read zero. I think your ammeter is your only problem.