delco 10si problem

joel rand · Jan 26, 2014

JD 60 with 12v neg ground system and delco 10si
hooked up for the first time today. Jumper from
Batt to #2 terminal on alternator. Indicator
light in wire from IGN to #1 terminal on
alternator. Light illuminated even with IGN off,
must be backfeeding through #2 terminal jumper?
Alternator was a new reman from NAPA. Charges
15amps and tractor runs and shuts off fine.
Alternator seemed warm after several minutes
hooked to battery. Continuity noted across
terminals #1 and #2. Did I get a bad alternator?
And what else have I potentially fried? If it is a
bad alternator and NAPA won"t replace should I
take it apart and just put in a new $10 regulator?
What about not hooking #2 to batt terminal?
Thanks for input.

old · Jan 26, 2014

Hook the #2 wire to the big stud post on the alternator. Next if the light is still on pull the 2 wire plug out then back in. Does light still stay on?? Almost sounds like you have a new bad alternator or you have the #1 wire hooked up to the wrong side of the ignition switch

Bob · Jan 26, 2014

1. So8nds like you've connected it up correctly.

2. It was never accidentally connected up (+) ground, I hope?

3. Could it be a so-called "one-wire alternator" that needs NOTHING connected to the #1 and @2 terminals?

4. If neither of the above, it's internal voltage regulator and/or diode trio is simply defective. Wouldn't be the FIRST new or "rebuilt" part to be bad "out of the box.

Janicholson · Jan 26, 2014

I believe it is a bad regulator in the alternator.
Take it back. The #1 terminal should be a ground when the ignition is off and the alternator is not turning. If there is voltage there from the alternator, it is "grounding" through the ignition system causing the light to glow. It should not.
When it starts, the VR should then put out voltage on that terminal causing the light to have 12 volts on both leads and thus not shine. It is just incorrect. Jim

Steve@Advance · Jan 26, 2014

Make sure the #1 wire is wired to the ign side of the switch. Unplug it from the alternator, ground it, switch off, no light, switch on, light lit.

If that checks out, most likely the diode trio is bad. It's easily tested with an ohm meter, but you have to disassemble the alternator to get to it, test out of circuit.

They should warranty it though, not unusual to get a bad alternator.

oldtanker · Jan 26, 2014

This is how it should be wired. Can be done with the diode or the light.

If everything is wired right take the alternator back.

Rick

gbs · Jan 26, 2014

disconnect #1 wire start tractor it shouldn't charge,while still running momentarily jump across #1 and#2 then remove it ,should charge as long as its running ,while running connect a test light to a #2 and touch #1 it shouldn't light ,shut off engine it should light, if so reg is working, if it charged on start up with #1 unhooked you may have gotten a 1 wire type,make sure you didn't get a 1 wire set-up that didn't have the reg term's plugged btdt

Jon Hagen · Jan 26, 2014

Do you have a proper plastic regulator plug in the alternator ?? Those "alternator harness repair plug kits" are avalible at most auto parts stores for around $3
Never fit an alternator with bare metal crimp on terminals on the regulator terminals. If the #1-#2 terminals touch then you will have a problem like you describe.
If the #2 terminal shorts to the alternator case, you will fry atleast the BAT to #2 wire, and maybe the entire tractor harness.
The plug kit is cheap insurance and makes your conversion look much more professional.

JDemaris · Jan 27, 2014

(quoted from post at 16:06:52 01/26/14) JD 60 with 12v neg ground system and delco 10si
hooked up for the first time today. Jumper from
Batt to #2 terminal on alternator. Indicator
light in wire from IGN to #1 terminal on
alternator. Light illuminated even with IGN off,
must be backfeeding through #2 terminal jumper?
.

That backfeeding in SI Delcos is usually caused by a bad diode trio. Cheap to buy and easy to put in. A bad trio will keep the "idiot light" glowing with the ignition turned "off." NOT to be confused with backfeed that occurs with the alternator charging thru the exciter circuit. THAT needs a single in-line diode. THAT or an automotive ignition switch with an "ACC" terminal.

RodinNS · Jan 27, 2014

If you're certain that there is no current flowing through the ignition switch and indicator light then I would say you have a problem in the alternator. Take it back and get it replaced. That's why you pay a bit more for a NAPA alt.
When you install the new one make certain that you have #2 hooked to the BAT terminal, the BAT terminal has a large conductor to thebattery side of the starter relay AND make sure the alternator case is grounded to the tractor chassis with a 12ga or larger wire. DO NOT rely on the pivot bolt to provide sufficient grounding to the chassis.

Rod

delco 10si problem

joel rand

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old

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Bob

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Janicholson

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Steve@Advance

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oldtanker

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gbs

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Jon Hagen

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JDemaris

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RodinNS

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