Power Surging

[Johntom]

I have a 2001 7.3 Crew Cab and after running it for a little the lights all seem to have a surge to them (brighter then dimmer) it is pretty noticeable at night. I shut the engine off, but turned the lights on and they stayed steady. as soon as i started the truck back up, the lights were doing it again. the alternator and batteries are good, any other ideas?

[RadarRider]

Originally Posted by Johntom

I have a 2001 7.3 Crew Cab and after running it for a little the lights all seem to have a surge to them (brighter then dimmer) it is pretty noticeable at night. I shut the engine off, but turned the lights on and they stayed steady. as soon as i started the truck back up, the lights were doing it again. the alternator and batteries are good, any other ideas?

What was your reading for the charging system? Almost sounds like a bad voltage regulator. They're internal inside the alt.

['powerstroke7.3]

Alternator is on its way out.

[bbboomer]

Mine did that too. I replaced the alternator but that didn't fix it. Mine had one battery that was going bad and that fixed the problem.

[RadarRider]

Originally Posted by bbboomer

Mine did that too. I replaced the alternator but that didn't fix it. Mine had one battery that was going bad and that fixed the problem.

Now that you mention it, I did have a problem with one battery a while back. It would read fine on my multimeter, but there were times when you tried to start it, it would seem weak & cause surging. Sometimes it would even spark @ the + terminal even though the connections were secure & would leave me stranded @ fuel stations for a good 15min.

[Johntom]

Just got back form the alternator shop. They said it was the regulator so they replaced it. Just wanted to say thanks for the ideas and put up what the answer was in case someone else has this problem in the future.

['powerstroke7.3]

There is a write up on PSN about rebuilding alternators if you are interested for future reference.

It will definatly save money in the future.