M151A2 smoking generator

[cry102]

Hello
I recently purchased an M151A2. I have driven it around the block a few times and noticed the voltmeter reading in the high white. A couple days ago i wanted to take it for a long drive and couple miles down the road i stoped to get gas and smelled smoke. I did not know where it was coming from so I continued on my trip. another couple of miles down the road i noticed the voltmeter was reading above the red indicator so I pulled over and opend the hood and found the generator smoking real bad. what would cause this problem and should i replace it? If i replace it should i go with a generator or switch to an altanator. the generator is a 60amp. Thank you for your help

 

[txdodge43man]

the M151a2 comes with a internaly regulated Altanator. What probably happend is something failed internaly with the altanator which cause it to over charge. Some shops can rebuild those but most will not touch it because it has a sealed internal regulator. I would replace it with another 60amp. some times you can find a deal but most go for 200.00 or more

 

[papakb]

The Prestolite and Leece-Neville 60 amp alternators are serviced by Southern Automotive. They produce the alternators for the military and will sell directly to the public. Here's a link to their website:

Southern Automotive Wholesalers, Inc.


The Prestolite / Leece-Neville website has a lot of information about the military AMA-5104UT alternators that we use. You may find some older AMA-5103 alternators still in the system but they are easily upgraded with a kit from Southern Automotive. This site also has some good training manuals you can download that explain how the electrical system works.

Alternator Series - Prestolite / Leece-Neville

Changing the regulator is a matter of removing 6 screws and is a simple task. Before you do, DISCONNECT THE BATTERYS. Another reminder, NEVER disconnect the batterys with the engine running. It's a guarantee that you'll have a bad alternator if you do.

Hope this helps,

Kurt

 

[Wile E. Coyote]

Kurt's dead right. Old-school mechanics would check to see if the generator was running by having the vehicle idling then disconnecting a battery terminal to see if the vehicle would still run. Great for a 50's generator - not so great for anything with an alternator, as the alternator will usually assume the battery needs the biggest charge the alternator is capable of putting out and will send the voltage into the 30+ range. Guages, electronic ignition modules and especially the alternator regulator itself really don't like that...and you let the smoke out.

Out of all the M151s and deuces at work and all the ones I've ever driven/used/owned -- I have far and away more problems with the Leece-Neville alternators than I do the Autolite ones. I think the military did too, as if I buy a pallet of electrical failures from GL - guaranteed most of them will be Leece-Neville. Odd really, when you consider the outfit is the leading producer of alternators for things like road construction equipment, generators, industrial machinery and so forth. Several I've tested will load down 120% - send the needle full into the red...and cause enough smoking belt squeal to set all the local coyotes off on a good howl.

Also, if you have dodgy batteries - maybe one that's got a bad cell that *usually* starts you every morning -- you're putting your charging system through some major pain and anguish. A battery with a bad or weak cell will always appear to the charging system as in need of a charge despite the fact the other cells in the battery are already at their ideal specific gravity. Basically that means the alternator's working a double shift all the time and you usually wind up boiling/gassing the batteries.

Tried changing out the regulators on several of the bad Leece-Nevilles but it never seems to be the regulator. Maybe it was just the one bad lot I had when I was playing around -- but still -- very unrewarding. In those cases the alternators simply *wouldn't* charge as opposed to overcharging, so perhaps a regulator changeout in the case of one pinning the charge into the red might work.