TheSamba.com :: View topic - Alternater 'sticks'/ question about different amp alts

Sun Aug 10, 2008 10:58 pm

Here's another strange, seemingly insignificant problem that I'm having. When I first start my diesel van, the battery light comes on and remains on until I start driving or rev the motor a bit. The voltage remains at about 12v until the alternator kicks on and the light goes out, at which point it jumps up a few volts.

Once I start going, it's fine and remains fine until I shut it down and start again.

Now, as I said in the title, it's like the alternator sticks. Of course it isn't mechanically sticking, and I can't imagine what mechanical problem could cause it to do this.

Should I pull it off and get it rebuilt (or buy another)?

Any ideas what could cause this?

And here's another question:

I've noticed that 90amp alternators are available. Mine, which claims to be making 60amps, doesn't do such a great job when I've got the headlights on, the fan blowing, the stereo going (with 200w amp), etc . . .
If were to also have my fridge on, an inverter powering my computer, the high beams going, and then the radiator fan decided to kick on, I'm sure that my battery would explode.

So, if I can get one of the fancy, higher output alternators, is that likely to create a significantly increased load on my poor little outrageously overworked engine?

I'm imagining that a nice rebuilt alternator would spin more freely, and that a bigger one might for that reason not actually be harder to turn.

As many of you understand, my van can barely push itself as it is.

Sun Aug 10, 2008 11:02 pm

To be clear, I should add that when I give the motor a little gas from idle and the alt comes on, I can let it go back to idling and I continue to get power.

Mon Aug 11, 2008 4:36 am

mine has done that for 12yrs including 1 reg/brush holder change. neter output of alt if 14.3 area i wouldnt sweat it.

Mon Aug 11, 2008 10:45 am

Normal, condition. If it drives you nuts, you can add an additional warning light to add load to excite the alt quicker. All the diesels exhibited this behavior. The gas models had an egr light or oxs light to add to the load. The Diesel has neither. The brake warning light and seat belt warning are tied to the oil pressure. These were all early versions of bulb checks. As far as more amps? If you have a camper and dual batteries I would consider the higher output alternator only as an upgrade to the charging system. Other wise a diesel has no elec loads when running. Once the battery is charged back up from starting. The alternator is basically along for the ride. You could run a diesel for a month without an alternator. Only the fuel cut off switch needs power.

Mon Aug 11, 2008 11:56 am

My 87 does the same thing, needs revs to get the lights out and start generating, I removed the alternator cleaned it etc ...same thing happens so no sweat!!!

Tue Aug 12, 2008 10:59 pm

Thanks for the replies!

Tue Aug 12, 2008 11:19 pm

rsxsr wrote: You could run a diesel for a month without an alternator. Only the fuel cut off switch needs power.
And actually, there is no doubt a manual replacement for that solenoid.
Al