Cucv alternator going bad?

[DieselStax]

I think my alternators going bad on my 86 m1008 but I wanted to ask here to make sure. Lately it's been making a chirping sound at idle and charges fine but the voltage goes down to 13 or below of I have the lights on or the heater on, or both. This is gen 1 by the way and It has new belts. The gen 1 hasn't come on to tell me that it's not charging. Thank you

 

[PAm1009]

You might have to adjust your belt there's room on the alternator bracket.. On the side note I miss rose valley lake I went to college in Williamsport it is beautiful around you

 

[Barrman]

Have you done the resistor bypass so the glow plugs are pulling off just the front battery? If so, with the cold temps you are having it could just be the after glow going on as the engine warms up and the alternator is already having to work pretty hard to charge up the battery after the pre glow. The chirps could just be the alternator taking the load and a slightly loose belt letting you hear it.

Either bypassed or not. If you start turning stuff on right away after start up, it will put a huge load on your battery and alternator. Waiting until the voltage gauge clicks up into the green after start up and stays there before turning on lights and the heater fan will help.

I would suggest you let the truck warm up and drive it around some. Then with everything off. Put a volt meter on the front battery terminals. It should be 14.4 volts at idle. If you are lower than that, you either have something drawing or a regulator going. If it is ok, start turning stuff on. The voltage will drop down some, but the alternator will start bringing it back up. It might also be a good idea to load test your batteries. This could just be a battery dying on you.

 

[m1ihc]

my m1009 had almost the same problem. the gen 1 light did not come and the gen 1 alternator stopped charging my battery. i ordered a rebuild kit and pulley from cucv electric. i replaced everything and it still would charge my battery. i found that i did not clean the rotor enough to make proper conection with the brushes i would replace at least the brushes and voltage regulator and clean all the internal connections in the alternator as well as the external conections to the alternator

 

[ARYankee]

Here is a really great thread from the CUCV stickies that will help you troubleshoot: http://www.steelsoldiers.com/showthread.php?54292-CUCV-alternator-symptoms-diagnosis-and-fix