2nd Gen Non-Engine/Transmission GEN dash light/ voltmeter acting crazy HELP

[cluckmaster]

Hey guys- was driving to Hurlock, MD this morning, and noticed my GEN (i guess generator/alternator) light was on. Dash voltmeter was on the notch below 14 (so I guess somewhere around 10 or 12). Stayed like that all the way, and then went on and off several times between Hurlock and home (about an hour). Shut her off for about ten minutes, then started back up to drive in to work, and the light was off and the meter read just over 14 the whole way in. Just walked out and started her up and she went up to 10 or 12, sat that way for a minute, then started slowly bouncing back and forth between 10 and 14. 5 or so. I don't want to go buy a $144 alternator unless it's actually bad. Any ideas whats going on?



Nopt sure if this is related, but I filled my tank a few days ago, and when I started up, the fuel gauge went crazy, bouncing all over. Shut it down, started back up ,and it climbed to full and has been good since.



Any info would be great. Hate for the alternator to die tonight after dark. THANKS! -Josh

 

[Missouri Mule]

The third time you started up it could of been your intake heaters lighting up on post cycle. That is the usual voltage readings that mine does on post cycle.

So you should have to address the first/second time it acted up.

If heaters acting could be intake temp sensor/relays/PCM

If charging system PCM (EVR)/battery temp sensor,wires/alternator/

connetors (battery terminals)/wires(broken, grounding out).

 

[cluckmaster]

Update- after work, went out, and everything was fine. No light, meter read 14. 5 or so. Yesterday, same stupid thing happened... . GEN light came on, meter read 10 or 12. Shut it down, got back in later and the light was gone and the meter read 14. 5 again. Then it happened again this morning. Lights and dash never dim or anything like that. The really funny thing is. . that I didn't put together until the second and third time it happened. . my pyro goes crazy whenever this happens, bouncing all over the place, but it always goes back to normal when the GEN light goes off and the meter reads normal again. Sooo... to sum up, I turn on the truck, GEN light comes on and meter reads low volts, and the pyro acts crazy. Shut it down for awhile, start it back up, and everything is normal. ???????

 

[cluckmaster]

Anybody know if there's a temp sensor on the grid heater that can go bad and keep the heater on continuously, or come on after truck is up to operating temp? Light came on and meter went down again this morning, but only after about an hour of driving. Pyro was acting funny the whole way in as well. Pulled the power wire from the fuse box (on empty hole in fuse box) and it killed the power to the pyro, but volts didn't go up on the meter. Shut down engine, started it back up, and GEN light was off, but meter was still low. ???

 

[cluckmaster]

Well... . I guess I'm am moron, b/c I changed the alternator and that was apparently the problem. Just thought that it wouldn't have been such an intermittant problem if the alt. was dying. hmmm. The pyro has been acting good so far since the change too. ? Wierd.

 

[Ruckuz]

hehe, good to see you found it. I had an alternator do some weird things too