Alternator not charing battery (dt466)

[Seeria]

The disconnects aside for a moment. Doing a 30 min idle test showed nothing wrong until the lights, wipes, blinkers (etc) were turned on, at which point the batteries dropped to 12.1. Went back up once these things are off. Waited a few hours before testing again (equalization) and batteries showed fine.

Had a guy tell us that there isn't anything wrong, this is normal. O.O to loose power that much when running the engine? What happens if I drive for an hour with lights on? Wouldn't the batteries die if the alt isn't giving them juice?

Doesn't it ruin the batteries to drop that low?

[chev49]

depends on alternator... after all, it was at idle.. and pulley size.. engines run at least 3 times idle speed during normal operation...

[Seeria]

Will try it again today. Warm her up, rev her and test. When we do actually drive the volt gage on the dash shows it sits just barely under the green mark (12 being white mark next to the green mark). But if I turn on blinkers while actually driving it drops below the 12 mark. Seems like it isn't seeing the dip in volt and not kicking in the alt to charge the batteries. That would be a regulator problem?

Will report back later with the reports from the digital voltmeter.

[wtd]

We're starting to go 'round in circles here - so to summarize -

Originally Posted by wtd

When the bus is running the voltmeter on the bus (or measured at the batteries with a multimeter) should be something north of 13 volts.

(from my previious post on page 1.) I'll add a little to that -"with no accessories on'.

If this isn't the case it could be the alternator or the regulator.
If you have an alternator with an internal regulator -

Originally Posted by wtd

The alternator is generally viewed as a 'works or it don't' part and replaced as a unit, rather than replacing components within it

If it has an external regulator, check to see if it's the alternator not putting out or the regulator not working right.

Would be a bit easier if we knew what kind of alternator you have.
Next time you poke your head under the hood, check the nameplate on the alternator.

Tom

[Seeria]

It had a delco in it and we think they said they were putting a new delco in, however, the receipt says nothing and we can't find a label on the alternator. Best we have is the vendor and product numbers.

Was going to do another test today but have a bunch of neighbors around so need to wait until tomorrow.

[wtd]

If it's a Delco just replace the alternator.

[Seeria]

Found the receipt on the bugger and it seems it is an International private label, which the guy says the regulator is inside the alt so have to replace whole thing. Spoke with him a bit and he agrees, he thinks it is the regulator, which he said they'd replace the alt for us, no cost. yeah, that's six states away.
Good thing is the alt is still under manufacture warranty. Bad thing is, nearest International parts place is too far to drive and we don't have the impact tool to replace the spool. As we're on the road we can't do repairs here at the campground, so not sure where we could switch out an alternator.

Have noticed there is a nick on one of the wires. Not sure if that's a big deal or not.

Going to do some checking around today, see if can find a few solutions that won't cost us $500 for alt replacement.

[Seeria]

Problem solved.
A recap for others that have similar problems. Batteries weren't getting a proper charge but alternator seemed to be working so after numerous talks with mechanics and forum folks, it was most often guessed the regulator was the problem.
After taking the vehicle to two shops in town, one an alternator specialist, we found that to be the problem. Our dt466 diesel international had a relatively new (6mth) old alternator which has the regulator inside. The alt was a "private label" from International, which we were told by a Int dealer this particular one tends to have regulator failures.

Replacing the alt with a brand new one fixed the problem of it sometimes not charging the batteries or charging barely enough.


Good thing for us is the alt was under warranty so total cost to replace was $30 (loved that...no full hour rate charge), took 15 minutes.

Hope this helps others with similar problems!! Thanks to you fine folks for the wonderful help.

[bus-bro]

[Seeria]

The fun part of this whole thing is the guy who did the final alt install for us (we didn't have tools and campground won't allow it). He made a thing called the generac which Jay Leno uses in one of his cars, if I understand him correctly. You should see the pics of him with Jay and those OMFG great looking cars. I think Jay has a car fetish. Or engine. Maybe both.