Charging issues with New alternator

[FamousBCB]

Hi all!

Have a 93 Deuce with a Cat3116 and recently installed a brand new 60 amp alternator. It was charging at 28V after installing it. Now after driving it about 150 miles I noticed the Volt gauge in the red. Checked charging and the alternator appears to be putting out 0 volts. Pulled the cover off the alternator and hooked a DVOM to the positive post and a known good ground and had only battery voltage, nothing more. Also, if I remove the positive cable the truck dies immediately. Could i have hooked something up wrong and killed the alternator? Did it just die? Any help would be greatly appreciated after spending $800 on alternator and $450 on batteries it stinks to have charging issues.

Much appreciated!

 

[glcaines]

You have an M35A3. Have you downloaded and read the TMs? TM 9-2320-386-24-1-1 has troubleshooting procedures for the Prestolite alternator in your truck. If you don't have a complete set of the TMs for your truck, you should go to www.jatonkam35s.com and download all of the M35A3 manuals you don't have. I have attached a copy of the wiring diagram for your truck.

 

[simp5782]

It is not getting the power on the exciter wire more than likely. Does it have power on the exciter? Military alternators are known to not be so great. Would have been better to put a brushless unit on the truck at a cost of only $200

 

[Katavic918]

If it's not your exciter wire it could be your voltage regulator. Thats the back plate held on by, I think 6 small screws. After going through 3 mil altrmators on 2 trucks I swapped both to Delco 21si 24v alternators for about $100 each. No problems since. You will need very minor modifications, none of which are permanent to to truck. Good luck.

 

[FamousBCB]

Thanks for all the comments. I'm trying to Download the TM for the deuce but it keeps saying error. Until then, which one is the exciter wire? When I disconnect the positive terminal the truck shuts off right away. I purchased the truck without an alternator, and I think I may have had the smaller wire off the starter solenoid (positive) hooked to the ground on the alternator. I may have killed the alternator regulator myself. *sigh*

 

[cattlerepairman]

The regulators are still available separately, aren't they? Pretty much plug and play , integrated with a new end cap, if I remember correctly?

 

[sue]

The regulators are still available separately, aren't they? Pretty much plug and play , integrated with a new end cap, if I remember correctly?

Just buy a 24-28 volt 60amp one wire alternator, $90-110

 

[FamousBCB]

replaced the regulator and it wasn't charging... started driving it and boom, gauge goes into the red and it's charging at 33 volts. seems fixed for now.

 

[cattlerepairman]

Uh..no... 26.8 to 28 volts for the charging voltage. 33 V is way too high.

 

[FamousBCB]

Obviously I adjusted it...