THE PORTAL HUB - Pinzgauers, Haflingers, Volvo 303s and more!

First day out in 2014 and the light pops on while driving 45. Now it comes on instantly everytime i start it. Power is very low!

First thing is check the molex correct? Then, check the brushes? How do i check the alternato brushes?

Section "O" starting at page 9 in the repair manual provides good instruction for R&R and repair and testing of the alternator.

I agree with suspecting the main molex corrector, along with checking battery connections and grounds.

The alternator brushes would not be first on my list unless i ascertained that the alternator is not putting out, especially as the truck just woke from its winter hibernation.

I agree with Edzz, start with the Molex. Then, in my experience, I'd replace the regulator (~$40) before suspecting the alternator itself. I've seen or heard of open alternator wiring and open rotors in the alternator. While there are ways to test and debug, they are not easy to describe without being at the vehicle.

So first, check to make certain that all wires going into the Molex (from the truck side) have good continuity all the way through the Molex to the terminals on the alternator. If you find problems here, they can cause other problems as well - arcing at the Molex can kill the regulator (and in my case, took out the rather expensive alternator, too). It is easy to overlook or ignore the Molex but many of us have suffered the consequences of doing so.

wire on the back of the alternator busted at the molex. fixed.

Good job finding the problem.

Ya thanks much.

The exposed copper oxidized at the crimp and deteriorated. I placed new crimps on all wires. Should be good for another 40 years.

Coat the whole terminal with grease (from wire insulation, over the crimp, to the end of the terminal) to protect from corrosion and they will last twice as long.

I just had the same thing (charging light stays on) happen yesterday. I'm glad I read this post because I knew the outer side of the Molex was clean but didn't think to check the inside. Took off the engine tin and found the same problem you had - the terminal on the red wire had corroded and the wire had fallen off. Relatively easy fix.

audiocontr - Thanks for posting and leading the way.

Because I went through just about the same thing, I wrote down some "good" readings after repair:

Bat 28.20v
DF 9.0 +/- 0.3v
D- 0.0v
D+ 28.46v