On the way home last night I got a check gauges light. Sure enough, the volt meter showed 8 volts. So I turned everything off and headed back to the shop. In route, I got an ABS light twice. It came on for a few seconds then went out for a few minutes, then did the same thing. Except after the second time it didn't come back on. Everything else appeared normal. When I got back to the shop, I shut it down and went and got a DVM. My batteries were showing 12.6 volts. I turned the key to the run position and the volt meter jumped up to just below the 14 mark as usual. I started it and put the DVM back on the batteries and it cycled between 12.66 and 14.25 as the grid heaters did their post heat cycle and steadied at 14.25 when the cycle completed.
Any ideas as to what is happening? Things to check?

 

Sometimes the wire harness at the back of the alternator needs attention.

My abs lights up when i drive through deeper puddles or mud.

 

Hey Cougar!

When you were testing it at your place did you throw a good heavy load at the alternator? Load it up - headlights, full heater fan, radio, whatever ya got and then see how the DVM behaves. It may just bomb and stay low with a big load on the alt. Check all the connections, of course, you probably already did. Other than that, maybe an internal problem with the alternator/diodes/brushes or something like that.

Cheers! and good luck!

Mike

 

I'm going to drive it around town today doing errands and see what shows. I checked for codes and there wasn't any. Just been pondering why the volt meter went to 8 instead of showing at least battery voltage. I checked out the grid heaters and it shows no sign of being stuck on for a long period. I wish the maintenance manual had better wiring diagrams

 

Alternator. This time it failed in a more "traditional" manor.

 

Can't believe no one in this state has an alternator. But, I got lucky and found a shop that was open and overhauls starter and alternators. He has all the parts in stock and said it would take him a couple hours to do it.

 

FWIW, the same Alternator was used across multiple platforms, the only difference is the pulley is an 8 rib.

I was running one off a 1990 Ram on mine for a long time.......

 

I have a spare for my 1st gen, but they are quite different. No problem though, I got mine rebuilt and it's up and running again. Just wondering what's going to break next.