Need help with battery overcharging

[84 C2B2]

I've gotten my 84 CUCV back on the road. It has slowly become a civilainized truck again. I'm running a GM 108 Amp alternator and all of the wiring harnesses are correct IAW the owners manual. I fried the two wires going to the juntion terminal on the firewall. Fusible links I believe. I'm certain this happened because the alternator pulley was installed incorrectly and smoked the belt which kept the batteries from being fully charged during intial engine startup. I think that the alt gave a full dose of juice once I corrected the pulley issue which fried the fusible links.

I installed a 2/0 wire directly from the alternator to the left battery positive lead. I now have battery juice boiling over slowing from only the left.

Does anybody have any problems with larger capacity alternators with stock wiring or what do I need to install to prevent overcharging of just the left battery?

Thanks,
Jerry

[moondoggie]

Good Day!

Unfortunately, I have no knowledge of CUCV

[dieselcrawler]

You didn't mention what model CUCV you have... the CUCV 1008, 1009, 1028, and 1031 had dual 100 amp alt's, and, with replacement of the starter, adn a few other things, can easily be made into a 12 volt only truck. I have done this with me CUCV 1028, it now has only one alt, and no resistors on the glow plugs, etc.
However, if you have the CUCV 1010, it's a whole difrent animal. I do not know much about the 1010, but I do know it has a far difrent charging system, as well as wiring system. I think it has one 24 volt, 200 amp alt, and is known for it's toasting one of the 2 batterys. My sugjestion, if you arn't concerned with keeping the truck orig, is change the wiring harness. Find a donar truck, from a simular year diesel, and change it all. In the cab, under the hood, all of it. you could still keep the tail light wiring, and head lights, I think, but in the long run, you'll save alot of headaches by changeing it all.
Hope this helps...
Greg

[84 C2B2]

Guess I need to add more info. It was a military truck with the two 100 AMP alternators. An M1008. I removed that system when I completely overhauled the truck. I used a donor vehicle and salvage parts also. It is now a standard civilain P/U.

The alternator smoked the belt since I didn't have the pulley installed properly. Didn't put the washer between the pulley and the cooling fan so it pulled the plastic cooling fan into the alternator and smoked it and the belt. Fixed that problem. Since the batteries were really low on power from cranking the new engine to life, I believe the alternator put out it's full charge and smoked my fusible links. That's been fixed but I just think that since I added the extra cable that it sends the charging to the left battery while the right battery plays catchup. I'm just concerned that if I take the 2/0 cable off I'm going to smoke more fusible links. I haven't tested the voltage output or engine to alternator case ground yet. My voltmeter is currently in packup since I moved.

Jerry