Over the last few days the charging system on my truck has been either working fine or not at all. Has anyone else seen this. Could it be an alternator problem, like brushes, or could it be with a voltage regulator or pcm.

Thanks for any info.
Jim

 

If it comes and goes as you are driving your heat grid has a bad relay. This happened to me and it appears not to be charging but it is working and the heat grid is taking all the power. Hope this helps. COLDONE-ALASKA

 

It could be all of the above , only testing can tell .
Then more info on guessing where to start testing , like age of battery , ALT. , how do the connections look at battery ?
Have someone hold the idle up around 1,000-1,200 RPM , while you use a screw driver handle , something not too heavy or hard , tap on ALT , see if gauge jumps , if it response to tapping on ALT then it is likely the brushes , the regulator is in the PCM , but really goes bad , many put an external regulator because they can not diagnose , this can be a cheaper way to get the ALT going , if the PCM is bad , but I recomend testing finding out what the problem is them if PCM is bad , that is an opption .
So the 2 most likely are connections + fuses [ fuseable links also ] then the brushes .
Heres a link for parts .


http://www.fostertruck.com/dodge/default.htm

 

I just went through a similar situation.Voltage would read good for a little while and drop to 0.Turning off and restarting the truck would start this all over again.I went to a shop and had it tested and was told the regulator was out and needed PCM.I got a new one and all seemed well for about 3 wks then it all started over.I sent PCM back and it was tested and sent back as all good.I then removed alternator and took it to test and was told it was bad so I had it rebuilt and voltage was back to normal.The original voltage test was done with alt. in truck so I am not sure if alt was originally bad or not.I would start by getting the alt checked on bench and go from there.

 

X2 on the alternator brushes.

 

It will be either batteries, cables, connections, the alternator, the key switch, or the voltage regulator. The PCM did not do much for the 5 speeds back in 92, so you are off the hook on any big bucks issue.

 

Should look at all connections and clean as necessary to make sure good circuits. Take Alternator off vehicle and have it bench tested. On vehicle testing has been problematic to say the least.