M600 Alternator Problems

[thynes]

Hi, New to the forum, already learned a ton about my basket case M600. It was actually delivered with several boxes of parts. So now I am stumped and I could use some help from alternator experts. I have a M600 that has a charging problem. The last owner said it would drain the battery and he had a battery cut off put in. I finally got the machine running last week. I bought it in pieces so I don't know for sure how everything goes together... Sure enough the battery was dead this morning after a full charge yesterday. The bobcat has alternator p/n 1102344, it is a 63 amp. This is not original to the machine, and looks to be a rebuilt, possibly 5 years old. However, I have the parts manual, and it has a crude, hard to read, schematic of the charging system, and I think I have everything hooked up correct. So yesterday I started it up, the amp meter showed an initial charge of about 40 amps then went to no charge; it blew a fuse (15 amp) on the wire from the "bat" terminal to the alternator and starter motor. I replaced the fuse, and wouldn't you know it, it blew again.... What is the amp rating for this fuse, it was missing when I got the machine, and I guessed and put a 15 amp in, but cant' find any specs on the correct value? So, I was feeling adventurous and had a fire extinguisher nearby, I jumped the fuse with a wire. No smoke but the voltage on the battery quickly ramped up past 14 volts. I disconnected things at 15+volts. Here is a link to a picture of similar Delco alternator that I have. http://www.ebay.com/itm/1100566-1A22-Original-Delco-Alternator-71-Chevy-Chevelle-Nova-Camero-Corvette-/360862612547 The alternator, according to my manuals, has 3 wires connected to it. - One to the "bat" - One to the "F" field - One to the ground However, there is an additional connector "R" on the brush block that currently doesn't have a connector. After some research, I am not sure it is needed, as I think it used primarily for the alternator idiot light, is this correct? Also, my external regulator has 4 connectors, only 3 are used, F, 2,3. Connection 4 is not used, is this correct? Could a bad regulator cause the battery to drain? I don't think it is the alternator because I had it installed for a week now, and only yesterday did I make the final electrical connections. For those of you still with me, one more question. The wire from the "bat" terminal goes into the wiring harness, presumably to the key switch, and it seems kind of small, about 18 or 16 gauge, I think it is original as it goes into the wiring harness, and I don't see any splices. Any help getting this charging would be greatly appreciated. Thanks, Tim in Mass

 

[mark18mwm]

I can't really help you with the alt with a external regulator problem. I just thought I would tell you if you would want to, you can really simplify the charging system by installing a one wire alt with a low rpm cut in. I had charging trouble on mine and did this and for me it was the way to go, I really like it. I know it's not original and the original system will work fine when it's working, this just simplifies things. I'm no wizard with alternators but it does seem to me like it is your regulator with it going over 15 volts. 14 should be normal to charge. To me a 15 amp fuse seems small for a alternator that is 63 amp. There is no fuse at all on mine, but mine has been severely cobbled over the years and I'm still trying to fix things like that as I can. Good luck.

 

[jerry]

If you end up replacing the regulator it would be better to just replace the alternator with a delco from the 8o's that had a built in regulator for about 40 bucks.

 

[donald73d]

If you end up replacing the regulator it would be better to just replace the alternator with a delco from the 8o's that had a built in regulator for about 40 bucks.

I agree a single wire alternator would be best. Bring your current alternator to a rebuild shop and tell them what you want and they should be able to come up with one that fits perfectly. A Delco would be best. Forget a Mando alternator. They can even customize the alternator for you a little bit. The alternator in my Bobcat was customized so it cuts in at a lower RPM but also gives a little less AMP output. But fine for me.

 

[thynes]

Yea, I never considered a single wire alternator. That would simplify things a bit. I may go that route , but only if I fail after I tinker with this setup some more... Tim in Mass

 

[shankatank58]

Yea, I never considered a single wire alternator. That would simplify things a bit. I may go that route , but only if I fail after I tinker with this setup some more... Tim in Mass

A bad regulator will definitely drain a battery overnight! Used to take (leave) the cover off and stick a matchbook in the points to keep it from draining. Remember to remove it or you'll run it dead. Don't know what a regulator costs today, but would probably be a quick easy fix. Don't know about the fuse; but 15 amp aint much.

 

[thynes]

A bad regulator will definitely drain a battery overnight! Used to take (leave) the cover off and stick a matchbook in the points to keep it from draining. Remember to remove it or you'll run it dead. Don't know what a regulator costs today, but would probably be a quick easy fix. Don't know about the fuse; but 15 amp aint much.

So, I finally got around to working on the alternator again last weekend. I put a new voltage regulator and all seems to be fine. The amp meter reads a charge and after 3 days the battery is not dead. It think I will consider this one done.

 

[thynes]

So, I finally got around to working on the alternator again last weekend. I put a new voltage regulator and all seems to be fine. The amp meter reads a charge and after 3 days the battery is not dead. It think I will consider this one done.

For future reference, the regulator was a Standard VR103T.