Ok I have hit a wall here. 87 W250. I have currently reground it from battery to the body. I have a new battery, new alternator and my truck refuses to maintain power. I jump it and as soon as I pull the other vehicle off it drains and dies if i do anything electrical. All my problems started when I reground it and put a cd player in the truck. When i first put the alternator in I had to jump it. Had a small electrical fire and two wires burnt up. It looks like they were off the main fuse line. The thick 14 gauge red and the 18 gauge orange. When they were disconnected I had no ignition so i repaired them with wire nuts. I was able to start it then. I am going crazy here. Snow is coming and I want to play. What do I do? Please do not be afraid to insult my (lack of) intelligence on the matter.

 

are you getting 12 volts at all the wires going to the alternator? i know if the wire are not getting power it would prevent the alternator from charging the battery.

 

The cd player may draw too much power causing the alternator to fail to maintain the battery

 

Have you checked the voltage regulator? I would also run a separate ground for the regulator as that is a common problem with these trucks. The regulator does not ground well enough thru the screw to the fire wall alone.
I have 2 wiring diagrams that disagree with each other (I don't know which is correct) but on one of them the 14 gauge red wire that comes off the fuse panel feeds the ignition and is also connected to the voltage regulator. What are the colors of the wires on your regulator?
I also show an 18 gauge orange wire that feeds the radio.

 

OK. I am going to reground the voltage regulator and see what happens. Any and all posts are appreciated, thanks guys.

 

I cannot find the voltage regulator? The haynes manual says in the engine compartment, real frickin helpful.

 

Maybe I wasn't clear when I mentioned that it was on the fire wall? The screw that doesn't ground it well enough also mounts it to the firewall. Right behind the engine usually. By the way, the regulator can be tested before you just buy a new one.

 

voltage regulator should look like this. it might be hiding behind the air filter

 

Thanks guys, I removed the air filter and found it. I was looking for a small box that said "voltage regulator" on it per the picture in my haynes manual. I pulled it, cleaned the metal, then put it back. I ran a ground wire from the top left post to a bolt on the carb mount. Then I hooked my car up to the battery, let it run for twenty minutes or so and started it. Then let the truck run for twenty. Sounded strong, turned it off then it wouldn't start again, the solenoid just clicked at me. I think I will run to wal-mart for an ohmmeter to test it. Runs for 12 bucks. Is there a different way to test it? A new voltage regulator runs for 30 bucks. This is frustrating.

 

Funny...not really because I am losing my hair. I am having pretty much the same problem with my 2002 Dodge Ram 1500 but the regulator is in the PCM. I know this is not the 3rd gen rams but if anyone had any ideas here I could use it.