Squealing belt / charging issue

They are identical. Only the passenger side NEEDS to be isolated ground, but the Army wanted to keep spares simplified, so they required them both to be the same. The condenser isn't needed on either one, and won't hurt on either one. It's just for radio noise suppression.

cucvrus you said you use ac delco 13g? what is the difference between them and 60g? Because i just bought a set of those thinking they were good.

I just replaced them all along the past 23 years with what was there when parts failed and that has served me well. I do know that you have to cut the 3/16" spades from the harness and add 1/4" spades. I don't like cutting harnesses and 13G's always worked for me. When they went bad I replaced them 1 at a time as they failed. Merry Christmas.

cucvrus said:

I just replaced them all along the past 23 years with what was there when parts failed and that has served me well. I do know that you have to cut the 3/16" spades from the harness and add 1/4" spades. I don't like cutting harnesses and 13G's always worked for me. When they went bad I replaced them 1 at a time as they failed. Merry Christmas.

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Yes, I had to cut the tabs a bit. When you said you have 13G, i thought I bought the wrong ones. Reading posts like that one from veteran CUCV owners makes me question myself.
Oh and Merry Christmas

Barrman said:

The -20 manual for the CUCV has a great 74 page electrical troubleshooting section. The very first thing it says for any electrical issue is to load test your batteries and make sure they are charged. Please do that first because everything else is dependent on them being good.

You wrote that a new belt made it all good for a few months. What kind of belt did you put on? I ask because my trucks eat belts like a dog gulping down a treat. Except for Gates belts. The NAPA version of Gates works as well. I have found all the other brands just don't last. It might be as simple as a new belt again. But, load test the batteries and get them charged before you do anything else.

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Good to know... my 85 M1008 eats up the driver's side alternator belt pretty quick.

Everyone uses 60gs, you just take a grinder and grind down the tabs... not a hard thing to do...

Difference is the 60gs are self limiting... iirc.

Thank you for the confirmation. When u bought these glowplugs, i picked the 60g not really remembering why they were supposed to be superior.

Better than grinding down the tabs, replace the connector so that it fits the 60gs. It's a standard .250 connector.

Ok....so I rebuilt the passenger's side alternator today. Still no Gen 2 light. Still not charging the battery. Here's the condensed version of what I've done today - still with no Gen 2 light and no charging.

* Tested continuity of the Gen 2 bulb - works.
* Tested continuity of the Gen 2 socket - works.
* Sanded the tabs of the socket.
* Tested continuity of the printed circuit - works. Sanded the exposed pieces and fixed a folded over piece. A small part was torn around the Gen 2 socket. I placed metal ducting tape around it to oversize it and eliminate any chance of the socket not connecting to the circuit.
* Tested continuity of the assembled instrument panel circuit (From pin to pin with circuit, socket, and bulb). - works.
* Tested the fuse (forget the number - one on the bottom of the board that is a part of the charging circuit. - works.
* Sanded and replaced all four of the battery terminals.
* Sanded and re-grounded the front battery to it's correct location on the radiator support in front of the battery.
* Checked a few fusible links.
* Took off the square multiple pin connector on the driver's side of the firewall (the one with a bolt in the center), degunked it and wire brushed the connectors.
* Sanded all connections that are connecting to the alternator.
* Tightened both alternator belts.
* Charged the rear battery by itself.

I'm at a loss. I still have a few things to check tomorrow (the diode above the heater controls and the Gen 2 relay). I could use some advice of how to check those, specifically the diode. It is in horrible condition (rust). Can it be jumped? Where would I find a replacement diode?

Guide me, please. With the help of my much more electically savvy stepdad, I believe there is no power making it to the alternator itself.

Front battery charges just fine. Test normal. Rear one tests low. Gets about 26.5 volts when tested across both.

I've tested continuity of all sorts of random places whether they are involved or not. I can't find the breakdown here.

When you say I rebuilt the alternator. Do you mean you did it? I had Gen 2 with no light and grounded the brown wire from the voltage regulator and the light lit. I took the Gen 2 alternator to the alternator shop. They mounted it in the bench tester, No light. So Ichanged the alternator with a rebuilt one the light came on and Gen 2 charged again. There is more to doing an alternator rebuild if you don't know what you are doing. Just an idea. If I am wrong I tried to help. Happy New year.

I did. I used a kit and followed the instructions from another user. With the alternator as is, rebuilt, and with another from another CUCV, nothing.

I don't doubt what you say. I just found out over the years many things are more in depth then they appear. Something as simple as an alternator has intricate parts that the laymen can not diagnose or correct. I would say it may be something that was overlooked by you. Not faulting. I spent $125. to get Gen 2 repaired for the Red Devil and that was why the Gen 2 light not lighting. I made the discovery by grounding out the brown wire that runs to the Gen 2 cluster. It lit when grounded out and meant that Gen was at fault. Electrical is my Achilles heel. But with another perfect operational CUCV I just use my test light and a lot of time to try and correct any issues. I do get by with a little help from my friends. And I also use the phone a friend option for advise. Good Luck. Happy New Year.

So I’m getting no power to the brown wire (exciter on passenger’s alternator).

I decided to trace the 24v exciter circuit for the Gen 2.

With a test light grounded to the - terminal of the rear battery...
1. + post of rear battery lights.
2. Cable at 24v bar lights.
3. All cables leaving bar light.
4. All cables light past fusible links.
5. # 12 fuse lights on both sides.
6. Skipped the instrument panel because I put it back in again ... but I know continuity is good because I checked it yesterday.
7. Brown/red wire going to the relay...lights very dimly. What’s that about? Or am I making an error on my end?

So, if I stab the wire coming from the instrument panel to the relay, the GEN 2 light comes on. So, I think I’m missing a ground somewhere. Right?

BUT...it’s 24v, so it cannot ground to the truck. The more I learn, the more lost I get.

Sounds like you have a poor connection in that circuit. A poor connection can look good with a meter, but once you put a decent load on it, it doesn't deliver the goods. Try running a known good jumper from a solid 24v source and see what you get.

I FOUND IT.

I traced all of the wires from the back of gen 2. One of the wires in the flat plug goes to the 24v bar. It was cut and capped short of connecting to the bar. One from the - post runs to the diamond shaped terminal on the firewall. It was disconnected. I connected those two and BINGO. Both gen lights came on with the switch, and went off when cranked. Voltmeter confirms that both are charging now.

Now I wonder why on Earth the previous owner disconnected them. Essentially, I've never had a working gen 2. It just took this long to kill the battery to the point that it wasn't able to crank itself anymore. Now, it fires immediately with near zero glowplug usage.

Thanks so much to those that offered tips. The TMs are a real asset.