Delco 10SI Alternator

[tomfg]

My truck came with a Delco 10-SI Alternator

I installed a rebuild kit in the Delco 10si today, as it was charging a steady
15+ volts.
New bearings, brush holder, regulator, screws, diode tree, etc.

Glad I tore it down. Front bearing was dry, and the brushes had about done wore out.

There's a resistor on my old parts, that's not included in the new parts. Am I suppose to re-use this resistor? It's the one in the photo below.
If I remember correctly, it test out at about 46 ohms.

It's set up as a "3-wire" unit.

Thanks.

[neto]

Sorry I have no clue. I wonder if they might know in the electrical forum? Is the rebuild a staight parts replacement deal?

[Ledslinger]

I've rebuilt hundreds of those, always reusing the resistor. I think it suppresses radio noise, or the condenser may be for that. Be sure you put the ground (non-insulated) screw in the right hole. I can remember rebuilding these when they first came out in about 1972 and were cutting edge technology.

[tomfg]

Happy New Year

Thanks for the replies. Glad to hear that you re-used them,
as I already have the unit buttoned up.
Hints of information I found on the Net suggest that those
resistors help the 3 wire units "excite" faster, and
they are not needed for the "one wire" setups.

[sigshooter]

Originally Posted by tomfg

Happy New Year

Thanks for the replies. Glad to hear that you re-used them,
as I already have the unit buttoned up.
Hints of information I found on the Net suggest that those
resistors help the 3 wire units "excite" faster, and
they are not needed for the "one wire" setups.

Maybe I can wire up one of those resistors to my wife........ to help excite her faster

[tomfg]

The alternator rebuild seems to be a sucess, and is regulating now.
Started it up, and on fast idle it was reading 14.94, and came
down slowly to about 14.8 something. Ran it thru the paces
with the high beams, and heater blower on high.
Still want to take it out on the road and see what happens
at cruising speed, but it's snowing and blowing......
maybe tomorrow.

Let me know if the "excitation" thing works....... believe
I have some parts in the garage to rig up something.

[Wrenchbender Ret]

Your gage must be reading high. It should not charge much if any over 14 volts.

[tomfg]

On the kit I purchased, it states that the
"regulator set point: 14.7 volts"

I believe my VOM meter is close, as it
was reading 12.56 volts at the battery
before I started the engine.

After I ran the the truck awhile, and the
heater, lights, etc., the voltage settled
in at 14.74 according to what I wrote
down. I'm anxious to see if it regulates
below 15 volts when I'm doing 55.

[Captainfab]

May I ask where you bought your rebuild kit for your alternator?

[tomfg]

Purchased it off of EBay..... Chinese parts. Hope it
last a few days. Wonder if US parts are still available
for these units. May get a spare alternator to
rebuild and have on hand....... fun project anyway.