Charging/alternator 58 Ford 861

On Saturday used tractor about a half a day. Done great. Yesterday I went to crank it to move it, and the battery seemed weak. I ran for about 30 minutes, went to crank it again battery was dead. Quick charge, got it cranked and back to the shop, checked the battery with multimeter while tractor was idling, it was Charging at 14 volts, so I thought, alternator is good. With everything off, I checked for a dead short, checked good. I bought this battery in June. Charged battery over night on 2 amp trickle charge. Today the battery was back to 100%. Hit the key fired right up. For s*#ts and giggles I put my multi meter back on the battery, at Idle it is charging about 15+ volts, the more you increase throttle the higher the charging volts go, as high as 20+ volts. Ive never seen this on an automobile. Is this normal.

Are you using an analog meter?

You cannot use a cheap DMM.

Dean

Not normal. Are you sure your multimeter is correct? If you're sure the meter is correct, then it sure seems like the alternator regulator has failed. The regulator should be replaceable.

If it is really overcharging like the meter says, you will hear the alternator whining, the housing will get too hot to touch, and the battery will get hot.

You don't want to run it like that, it will damage the battery if it hasn't already, can even cause it to explode.

Might want to have the battery load tested, see where you stand on it.

If that is an internal regulator alternator, you can take it to the auto supply and get it tested.

If it is an external regulated alt, the regulator may be bad or the base lost it's ground.

Are you using the delco 10si alternator??
Are you trying to run it in the 1 wire configuration??

If yes......
Install a wire from the #2 spade to the battery post on back of alternator.
This will tell the alternator to shut off at 14 volts.

Sounds like the sensing wire is not hooked up or the V.R. has gone bad since it is over charging big time and will fry the battery if it hasn't already fried the battery

(quoted from post at 09:50:34 10/12/20) Are you using an analog meter?

You cannot use a cheap DMM.

Dean

Click to expand...

Im using a Klein MM300 that use for my work. Its not way expensive but not cheap either.

If it is really overcharging like the meter says, you will hear the alternator whining, the housing will get too hot to touch, and the battery will get hot.

You don't want to run it like that, it will damage the battery if it hasn't already, can even cause it to explode.

Might want to have the battery load tested, see where you stand on it.

If that is an internal regulator alternator, you can take it to the auto supply and get it tested.

If it is an external regulated alt, the regulator may be bad or the base lost it's ground.

Click to expand...

Its an alternator with internal regulator. I have heard no whining from the alt.

PostPosted: Mon Oct 12, 2020 9:40 am Post subject: Re: Charging/alternator 58 Ford 861
Are you using the delco 10si alternator??
Are you trying to run it in the 1 wire configuration??

If yes......
Install a wire from the #2 spade to the battery post on back of alternator.
This will tell the alternator to shut off at 14 volts.

Click to expand...

Yes its the 3 wire Delco alt. Number two wire loops back to the battery terminal wire.

Good chance the V.R. is bad so it needs to be repaired or replaced

(quoted from post at 13:52:40 10/12/20) Good chance the V.R. is bad so it needs to be repaired or replaced

Click to expand...

IF, I have wired in my diode backwards on the excite 1 wire, would that cause the overcharging?

No. The excite wire just turns the alternator on when you start the engine. If diode is backward the alternator would likely not start charging at all.