I have a 1976 E350 Motorhome and ive been experiencing some charging problems.

On my way out to the desert I noticed my dash gauges were fluctuating and my headlights went dim while driving.

I pulled over to take a peek and heard the alternator making unusual noises so I assumed the alternator went bad. I tried to restart the motorhome and of course it would not restart so I got a jump and was on my way to the nearest parts house.

I replaced the alternator and charged the battery on the side of the road and everything seemed fine but the same thing happened on my way back from the desert, so I picked up a new battery assuming it had an internal short.

When I got back home I replaced the voltage regulator for good measure and because it was inexpensive.

Here I am a week later and the battery is still not charging.

I have 12.6 Volts when the vehicle is off and it drops down to 12.2 -12.4 when running.

I checked all the fuse links and voltage at the back of the alternator (black) with the vehicle off, it reads 12.6 volts.

The Field wire (orange) tests good at the voltage regulator and the back of the Alternator with the vehicle running.

The Ignition wire (green/red) also tests good at the voltage regulator with the ignition in the "on" position.

All ground straps and connections appear to be solid and in good condition.

The only thing that does not have power at anytime is the (white) wire on the back of the Alternator.

Can anyone please clue me in on what my problem might be?

Thank you for your time and experience in advance!

 

What voltage do you have on the orange field wire with the engine running? There should be a yellow wire also going to the "A" terminal of the regulator. It should have 12v all the time on it.

 

The field (orange wire) shows 12 volts after the vehicle is started.

The yellow wire shows 12 volts at all times.

Thank you for your help.

 

If the field wire shows 12v, then the alternator should be wide open full output. If you want to do a test, take the field off the alternator and tape it. Then take a scrap piece of wire and hook it to the "f" terminal of the alternator(field terminal) and then get the engine started, and then touch this wire to the bat +. You should hear a little difference in the way the alternator sounds, and your voltage on the battery should jump way up, sometimes it will hit 15v. If it doesn't do this, and you are sure your "bat" wire is hooked to the battery, then the alternator is bad.

 

Ill do that this weekend when I have a little more time and ill be sure to post the results.

 

So after screwing around with this thing for the better part of 2 weeks, it just ended up being another bad alternator. Replaced it with another Reman and now im getting 14.5 V.

Thank You for your help Franklin2