Wiring a GM alternator

The backhoe I bought has a GM alternator.
It isn’t charging.
I plan to rewire everything.
It still has the voltage reg and wiring from it and the new spliced wiring for the alternator.
Mice have had their way as well.
Steve I’ll. Helped me wire the last one with a good diagram.
I used a marker light from the parts store in the system.
I’m seeing neat little round LED indicator lights for sale.
Will one of these work.
Would it hold up in the elements?
I’m trying to keep this neat.

im4racin wrote: A led wont work for the indicator light in that circuit. You could use a single wire alt from Napa. 213-4011sw. They only need the heavy charge wire.

Thank you. I wondered if LED would work or not?
If it turns out this alternator doesn’t work I may do that.
I think I’ll pull it and have it tester first thing.

Edited by Thad in AR. - 18 Feb 2022 at 6:46am

Codger wrote: Probably a 10DN series alternator. As suggested replace with a 10SI, (Systems Integrated)  internally regulated type and do away with the external regulator circuitry. Later models are one wire only and utilize self excitation to vary field current. Check for "cut in" rpm as I've seen many not start charging till the engine is revved far too high for my liking. They are fine once the exciter circuit is enabled.  If you have an ammeter you will be set and if not, one can be incorporated easily enough.

It has a 10si now. It is not charging. The wiring is a mess as it still has the old original external regulator and wiring.
I’m gonna remove it all and start from scratch.

Thad , the 40 year old alternators had an external regulator... Before 1980, GM switched to the 10SI with INTERNAL regulator. That was the industry standard for years.. About 2000 they came up with the CS130 ( smaller) alternators, then later came up with the "MINI" which is very popular now.. Almost everything built after 1990 has an internal regulator.......... You can get a new "MINI" with 3 wire or single wire feed.... Just might need to modify the MOUNT......... (Personally, i have been using the CS130 alternators for 15 years on ALL tractors).

Edited by steve(ill) - 18 Feb 2022 at 8:53am

I have a CA Allis that I am installing a CS130 alternator , I do not want the one wire system, so if LED light will not work, so just purchase any filiment type light, will that work for indicator light ?

Here is the "ONE WIRE" the guys are talking about... Just GUT everything and one 1 wire to the POSITIVE battery wire.

Steve-   thanx for the great info, wonderful to have a person like yourself, I will be using this for  wiring project

100 OHM, 10 WATT resistor ....

jaybmiller wrote: this !!! Yes it’s already swapped to positive ground TO---> positive ground ????? NO,NO,No !!! BIG problem there.. 99.44% of ALL alternators are NEGATIVE ground Be 100% sure the -ve of battery is grounded. Please report back once you've confirmed

Was in a hurry Jay.
I fixed it.
Yes it’s negative ground

Coke-in-MN wrote: I have all the 10SI alternators I use on equipment just wired with jumper from battery wire to the one terminal . Was wondering WHY a resistor is needed in that jumper wire ?

I thought it would drain the battery while sitting???

steve(ill) wrote: Here is the "ONE WIRE" the guys are talking about... Just GUT everything and one 1 wire to the POSITIVE battery wire.

I have all the 10SI alternators I use on equipment just wired with jumper from battery wire to the one terminal . Was wondering WHY a resistor is needed in that jumper wire ?

Edited by steve(ill) - 18 Feb 2022 at 1:36pm

AC... that is a 10SI alternator that puts out 63 amps ... and probably built 30 years ago... There were several "updates" after that to increase the amp output... Same basic alternator with INTERNAL REG.

the 10Si internal diodes keep the flow from grounding out , the jumper wire without resistor will sense voltage from bat to that terminal and internals of regulator will turn on alternator . 
 I have been running a 10SI on my HD5G for 20 years or longer , and the alternator on my 715B is wired the same except for tachometer it has a separate tab to power the tach .
 On my White Super Mustang dump truck also ditched the 35A Leis Nevil alternator with + ground and changed to 10SI using the same setup of single wire with no resistor . 
 On the HD5 - 2-71 the RPM is low so need to throttle up to get it to cycle into charge mode after starting but it will cut back and regulate fine after that initial switching on at higher RPM