Generator not charging

Bobber · Post by **Bobber** » Fri Jan 29, 2016 10:52 pm

OK, here we go. I bought everything at MWM so I know I have good/correct stuff. I polarized the gen. tested the generator output via Wes' method, it put out 32 volts. Hooked up solid state voltage regulator, the voltage meter, the one you use the spider on. At first I had the needle in the yellow and barely in the green. But when I checked the voltage with a VOM meter I only had 20-22 volts. It was a ground problem. The connections between the motor mount and block wasn't sanded bare. fixed that and I had the needle buried into the green and had 24-26 volts. Now it's about 10 miles later and the needle sinks back into the yellow. I cleaned the grounds between the block and motor mount, battery and frame, the bezel in the cluster dash. Battery connections are solid, any ideas? I checked the volts on the starter when I check for voltage.
Thanks in advance

Post by **wesk** » Fri Jan 29, 2016 11:59 pm

The first thing you do is isolate the problem. Full field the generator again. If it is ok then continue troubleshooting the connections, harness and regulator.

Don't overlook the ground between the generator and the regulator. I know the harness shield is suppose to do that but it can do that only if there's no paint between the shield and the connectors and no paint or corrosion between the connectors of the harness and the receptacles on the regulator and generator.

If you reach an impass with the generator ok and the harness and connections checking good you are back to the regulator. As far as I know none of the vendors will take back a transistorized regulator. There are no published manuals on the transistorized regulator. This is why I do not buy them or try to work on them. The mechanical regulators do just fine and have tech data and parts for repairs.

Bobber · Post by **Bobber** » Sat Jan 30, 2016 12:40 pm

Thanks Wes

Bobber · Post by **Bobber** » Sat Jan 30, 2016 1:49 pm

Would a continuity test with an VOM be sufficient to test the cable from the Gen to the voltage reg?

Bobber · Post by **Bobber** » Sat Jan 30, 2016 1:50 pm

Has anyone heard of the success rate of the solid state regulator? I haven't read anything negative about them.

Post by **wesk** » Sat Jan 30, 2016 9:31 pm

The Army switched to them because they were more reliable and, at the time, cheaper. They were an XB3 item from supply. That means they were not repairable and were a throw away item. The 24V 25 Amp system has been out of use over30 years and the production of spare parts for that system ended about the same time. The nos stuff on the market is only reliable as it,s conditions of storage allow it to be. They are usually (NOS) pretty dependable for awhile. But as I said there is no spare parts, or manuals to support them. They cost 3 to 4 times their original value today and are still a throw away item when they break.

4x4M38 · Post by **4x4M38** » Sun Jan 31, 2016 12:20 am

Wes,
Would you give your opinion on the non solid state regulators
both used and "nos" as being offered on various venues
versus the solid state units?

Understand it would be a personal opinion

Post by **wesk** » Sun Jan 31, 2016 1:32 am

I think my opinion of solid state vs mechanical is clear above.

As for the quality of mechanical rebuilt units and used units from vendors I cannot offer one. I have never bought a rebuilt mechanical regulator from any vendor. I have bought many used from flea markets and other non-formal vending types and opened the lid and knew exactly what I was buying. I won't pay more than $30 to $40 dollars for a used one that looks very good under the cover.

4x4M38 · Post by **4x4M38** » Sun Jan 31, 2016 9:42 am

Thanks Wes,
That's the kind of guidance I was looking for.

There seem to quite a few that have surfaced lately
labeled as working when removed. Without interior
photos it sounds like one should steer clear.

Post by **wesk** » Sun Jan 31, 2016 12:20 pm

An interior photo of a solid state regulator won't help you much. The damage that can make them useless may never show.

You can usually spot overheated, corroded and pitted components of the mechanical regulator very easily in good photos.

4x4M38 · Post by **4x4M38** » Sun Jan 31, 2016 3:19 pm

Yes Mechsnical was what I meant.

Bobber · Post by **Bobber** » Sun Jan 31, 2016 5:17 pm

Gen tested good, I have a new cable coming in the mail. The cable came with the jeep in a box of used stuff. Most of it that the PO acquired was either useless or wrong for that jeep. This cable looked OK to me in the beginning, but after having ground issues before, I think this cable is suspect. For me, In my opinion, I'll stick to the throw away model because that's about what I know. If I had some one to hold my hand, I would venture out to the mechanical regulator.

Thanks Wes, I'll be sure to update this thread when I have results. Threads like these keep me going. I've learned a ton.

Bobber · Post by **Bobber** » Fri Feb 05, 2016 7:33 pm

We, new cable was not the problem. looks like I'll do some more thinking and head scratching. I hopes not the solid state voltage regulator.
Thanks

4x4M38 · Post by **4x4M38** » Fri Feb 05, 2016 8:42 pm

Rusty,
I've read back through the whole posts.

I don't see where you checked the ground between
the regulator and frame. Maybe I'm missing
something.

Post by **wesk** » Sat Feb 06, 2016 2:36 am

There is an engine to frame ground strap and there are four voltage regulator insulator ground straps.