i have a ford e150 conversion van and when the car is running the volts on the volt guage goes from 12 or so down to 8 back and forth making the van want to stall and sometimes does especially when i am say backing out of the driveway and when sitting at a light it fluctuates from 8 to 12 or so. Anyone have any idea what might be causing this it seems to make the van not run so good...thanks for any help or ideas
Mike 1992 e150 conversion van..302 engine

 

Sounds like a bad alternator.

 

Ditto that. When the brushes get worn down they sometimes intermittently make or break contact causing it to start and stop charging. Sounds like probably what you've got there.

 

do i need to replace the whole alt or can you replace the brushes?
Thanks

 

You can try just a brush replacement, especially if money is tight. The hard thing is usually finding them. You'll most likely have to find an alternator shop that will sell parts. When I was young (a while ago now) they sometimes had 'em at the "real" auto parts stores (read as: Not Auto Zone). The last few years though, I've had to hit the specialty shops. Fortunately, here in Nashville there's a friendly one that I've dealt with a lot, and the brushes are dirt cheap (sometimes free). It's not a hard job if you are reasonably mechanically inclined. Mostly remember to mark/score the case halves so that you can get everything lined up right. I'm not going to go into it at the moment, but if you can find brushes and want to tackle it, I'll be glad to give you a step-by-step, either in this forum or by email.

 

i will go around and see if i can find the brushes i never done that before but am willing to give it a try
Thanks for any help you can provide
Mike

 

I buy brushes from NAPA when I need them.

 

A more detailed description of the voltage change over time might be helpful. If it is a rapid back and forth fluctuation then I could see it being bad brushes.

<p>If it *is* the brushes, you can take the alternator apart and you will often find that you can fix the problem without replacing the brushes. It may be the copper braid that runs to the brush has broken off and just needs to be re-attached, or rigged back in place. If you can't find brushes for your particular alternator, or they are pretty expensive, try finding any place that supplies new or used brushes for electric motors. As long as it is more or less the same shape of brush, it should get the job done. I once replaced a brush with a bolt. I don't suggest doing that. It doesn't work real well.

I would try running the car with the alternator disconnected to see if the issue is still there... I would probably replace the voltage regulator just to see what happens, because that's easier than messing with the alternator, not too expensive, and you never know when your next electrical issue will arise when you would like to replace the voltage regulator just to see what happens... this way, you'll already have a spare voltage regulator on hand!