Irregular Voltage from Alternator

[LowTech]

So I've been having some issues w/ the Alt. Sometimes it puts out voltage in the high 13s and sometimes nothing. Depending on when I've checked it I have thought it was working great and other times not at all.
Did a 50 mile one way run to get a battery for our other vehicle (which they ended up not having) and coming back after dark the voltage was reading 12.4v w/ the headlights on. We ended up spending the night in a parking lot while a sand storm raged outside. The next day got a jump and drove until reaching camp. Voltage was low when we arrived but the e-pump was still pushing.
Did some testing and got the voltage to kick up when I moved the heavy gauge wire from the alt to the batt, though "Found it!" Pulled that wire off cleaned the ends (not really corroded) and reattached.
I let it sit on the trickle charger for a couple days and then started it today. This time I did a bit move testing at idle and at higher rpms as well as from the alt and the battery terminals.
The reading were the same from the terminals and the alt itself but the voltage ranged from the low 12v to high 13.9v and really quickly.

Does this sound like a bad regulator? Or is there something else that could cause this?

 

[Kdo58]

3g upgrade is the best option

 

[LowTech]

Not sure what that is, I'll have to read some threads. I do have the ambo version of the alternator.

 

[The_Josh_Bear]

Sounds like a bad regulator, or a bad sense wire(I don't remember the color). This would be the small gauge wire that goes to the fender solenoid or the battery to "sense" the voltage draw on the system, which ups the voltage to charge more.

Does the ambulance package have the external or internal reg?

 

[Cubey]

3g upgrade is the best option

Vans got 3g starting in 1992. (edit: except ambulance)

 

[Cubey]

Does the ambulance package have the external or internal reg?

A special external, it looks like.

You must be registered for see images attach

 

[LowTech]

Thanks @Cubey. Yes I believe it's an external one. I think it only has one smaller gauge wire and that goes to a plug I found behind the driver's side batt. It was unplugged, probably for years, and lights the cluster indicator for discharging. I did plug it to see if it made any difference a while back and had no change other than it illuminating in the cluster and then staying that way.
There is an aftermarket 3 light panel that's wired to the charging system somehow that shows low voltage/ ok / and over charge (red/green/red lights). Those lights had been working until recently, now they just stay on the first red.

 

[The_Josh_Bear]

A special external, it looks like.

You must be registered for see images attach

Daaaaaaang, a 3G swap is cheaper than just that regulator!

 

[LowTech]

Found it!!! The one little wire that connects to the regulator (just like the regulator @Cubey linked) was just sitting there. The nut and star washer were still there and the ring terminal was just setting on the post. So I removed them installed the ring terminal / star washer / nut and now the voltage is steady.
Once I picked the rpms enough the alt kick in and started putting out strong (13.9-14v) steady voltage.

No insult @Jesus Freak but it was some Florida boys that did the wrenching on this rig for my mom before I moved it out west and began fixing things correctly. :***:

Now to get those sleeves and stop the fuel leak.

 

[Jesus Freak]

HEY!

Found it!!! The one little wire that connects to the regulator (just like the regulator @Cubey linked) was just sitting there. The nut and star washer were still there and the ring terminal was just setting on the post. So I removed them installed the ring terminal / star washer / nut and now the voltage is steady.
Once I picked the rpms enough the alt kick in and started putting out strong (13.9-14v) steady voltage.

No insult @Jesus Freak but it was some Florida boys that did the wrenching on this rig for my mom before I moved it out west and began fixing things correctly. :***:

Now to get those sleeves and stop the fuel leak.

HEY!, I was really impressed with how I got that thing wired.........ughhhh......I mean my buddy did it, YEAH! That's it my BUDDY did it.