Alternator problems

[Cableclown22]

Iv got an 86 with a 2.5 and for some reason it dies every time the alternator starts charging the battery. The alternator is good and iv replaced about everything possible related to it and checked all grounds I can find.  Running a wire to the battery it kills the engine. The only way I can drive it is with a solar panel keeping the battery charged. What could possibly be the issue?

[eaglescout526]

Oooo this is a tricky one. @SoCalManche is having a similar issue that is still trying to solve. Except his runs and drives. 
 

Well let’s start at the top. Is the battery itself good?

[Cableclown22]

The battery is good 

 

[eaglescout526]

Can you keep the truck going long enough to get a multimeter to the battery to see if it’s outputting? I’m almost wondering if something in between the battery and the alt is bad. 
 

without the solar panel. 

[Cableclown22]

It dies pretty much immediately.

[eaglescout526]

Hmmm. As soon as it dies, have you check the voltage at the battery?

[yxmj]

What happens if......You get it running.....you remove a battery cable from the battery......does it continue to run or die?

[eaglescout526]

3 minutes ago, yxmj said:

you remove a battery cable from the battery

I killed an REM with this trick

[yxmj]

It will be fine

and it will tell you right away if the problem is the battery or the alt.....no guessing

[schardein]

I don't understand "it dies every time the alternator starts charging the battery".  Your alternator is charging from the  moment the engine starts.  When you start the engine, how long does it run before it dies?  What makes you think the alternator started charging and stalled the engine?

[Eagle]

4 hours ago, schardein said:

I don't understand "it dies every time the alternator starts charging the battery".  Your alternator is charging from the  moment the engine starts.  When you start the engine, how long does it run before it dies?  What makes you think the alternator started charging and stalled the engine?

 

Also, what does "Running a wire to the battery it kills the engine." mean? Are you saying that you have to disconnect the alternator before you can start the engine?

[Cableclown22]

It has a gm single wire alternator and it will start with the power wire to the alternator connected but dies in 10 seconds or less. Alternator charges at 14.5 volts 

[eaglescout526]

Have you tested any of the wiring for a short, resistance or bad connection?