Frozen Alternator

[Stan&Jacquie]

When an alternator is frozen causing it to throw the belt what needs to be repaired? Is it usually just the pulley Or is it usually something gone wrong inside the alternator?

Is it worthwhile to have the alt rebuilt or is it more sensible to replace the whole thing? My unit is out of warranty.

[Ray,IN]

It is not the pulley, something like a bearing or rotor is bad when the alternator will not turn by hand. A rebuilt will cost about 2/3 the cost of a new unit, which normally comes with a 1 yr warranty, rebuilds usually only have a 90 day warranty at best.
Remove your bad alternator and take it with you to a truck parts store, often they can match it at lower cost than from the vehicle mfgr.
OTOH, you may copy the make/model numbers off the data tag and shop online.

[Sky_Boss]

Originally Posted by Ray,IN

It is not the pulley, something like a bearing or rotor is bad when the alternator will not turn by hand. A rebuilt will cost about 2/3 the cost of a new unit, which normally comes with a 1 yr warranty, rebuilds usually only have a 90 day warranty at best.
Remove your bad alternator and take it with you to a truck parts store, often they can match it at lower cost than from the vehicle mfgr.
OTOH, you may copy the make/model numbers off the data tag and shop online.

Yep...Agree.

[slickest1]

Originally Posted by Ray,IN

It is not the pulley, something like a bearing or rotor is bad when the alternator will not turn by hand. A rebuilt will cost about 2/3 the cost of a new unit, which normally comes with a 1 yr warranty, rebuilds usually only have a 90 day warranty at best.
Remove your bad alternator and take it with you to a truck parts store, often they can match it at lower cost than from the vehicle mfgr.
OTOH, you may copy the make/model numbers off the data tag and shop online.

Good advice!

[Stan&Jacquie]

Originally Posted by Ray,IN

It is not the pulley, something like a bearing or rotor is bad when the alternator will not turn by hand. A rebuilt will cost about 2/3 the cost of a new unit, which normally comes with a 1 yr warranty, rebuilds usually only have a 90 day warranty at best.
Remove your bad alternator and take it with you to a truck parts store, often they can match it at lower cost than from the vehicle mfgr.
OTOH, you may copy the make/model numbers off the data tag and shop online.

Sounds like a plan....thanks for squaring me away!

[Bigd9]

Just another thought:

A couple years ago I took the alternator from our last coach to a small starter/alternator rebuilding shop in the next town. They completely rebuilt it and increased the amperage a bit. The alternator looked brand new when I got it back two days later. The cost was 60% of the NAPA rebuilt or remanufactured alternator price. He told me at that time, he rebuilt them and then sold them to a company that then packaged and resold them to auto parts stores.

As far as a warranty goes, the way I look at it, if it is going to go bad, it will go bad early on, or late in life. To me a 90 day vs a 360 day warranty is about the same thing.

[barmcd]

I know the original Leece-Neville alternators on some coaches are not the same as ones sold today and should be rebuilt instead of replaced. The new alternators cause all kinds of problems.

[mackwrench]

Should go with out saying, but be sure to replace belt as well....And if tensioner has lots of miles, good to replace it as well.

I've seen worn belt tensioner cause altnatenator bearing failure. The belt slaps and on/off slippage is hard on all belt driven components.
Spend a few minutes looking at this and it'll help understand why at the 1:40 mark in video:

https://youtu.be/fFN3pr-OHSQ

[slickest1]

The fellow that rebuilt my alternator said that one reason they fail prematurely is that the engine is mounted backward and the spray from wet roads gets into the alternator more so than when they are facing frontward. That combined with an rv sitting for long periods leads to problems.
Mine was very rusty inside so he gave me an alternator that was already rebuilt.
I don't know if that is the case but it made sense to me.

[twinboat]

Originally Posted by mackwrench

Should go with out saying, but be sure to replace belt as well....And if tensioner has lots of miles, good to replace it as well.

I've seen worn belt tensioner cause altnatenator bearing failure. The belt slaps and on/off slippage is hard on all belt driven components.
Spend a few minutes looking at this and it'll help understand why at the 1:40 mark in video:

https://youtu.be/fFN3pr-OHSQ

The OP has another post running about throwing the belt. A few of us recommended he give the alternator a spin, before replacing the belt. I guess he did.

[Bigd9]

Originally Posted by mackwrench

Should go with out saying, but be sure to replace belt as well....And if tensioner has lots of miles, good to replace it as well.

I've seen worn belt tensioner cause altnatenator bearing failure. The belt slaps and on/off slippage is hard on all belt driven components.
Spend a few minutes looking at this and it'll help understand why at the 1:40 mark in video:

https://youtu.be/fFN3pr-OHSQ

Great suggestion!

[4Fingers]

Most engines also power the water pump with this same belt. Give it a check to make sure it spin without any grating or grinding.

Happy Motoring
Don & Susan