Belt squeak. Alternator or glow plugs?

[ZsZ]

Recently my alternator belt started to squeak badly on startups (1Z m-tdi with the JX dual V-belt setup and 90A diesel alt.) So I went and changed the belt. With the new belt it still squeaked regardless however tight I tensioned the belt.

Checked the alternator, there was a plastic sleeve on the rear bearing that was a bit loose, shimmed it with a strip of beer can, and coals were worn so did put in a spare voltage regulator.
The squeak was still there.

Now I removed the fuse of the glow plugs (still JX setup with AAZ relay and spliced onto the tdi wiring bridge) and the squeak is gone.

My next move will be testing the draw with a clamp meter. Any other testing I should do to decide if the alternator or the glow plugs are bad?

[ZsZ]

Checked the current.
The draw was over 70A after turning the key on, that is dropped to around 50Amps.
Tested each glow plug, they all measured 20A on start, which dropped to 10A glowing.

[mioba]

could well be the water pump is on its way out.
Might be worth getting the alternator refurbed - the bearings at least.

[ZsZ]

It is defo the alternator belt which was squeaking. It was hot and smelly.
The bearings were fine, added some grease into them.
I will dig up my old 65A alt I kept for spares to check with it.
This alt was refurbished a few years ago - not sure when and how many kms I ran on it. But will get it tested just need to get it to the specialists

[muttleypup]

Recently been through similar (twin belt setup on a 1Y). Even with new belt and a new alternator it still squeaked. Mine turned out to be the bottom pulleys on the water pump being badly worn. Managed to find new ones in Spain from Areacamper and squeak has gone.

[ZsZ]

on TheSamba they suggested the alt pulley is worn and the belt sits too low:

Might be the case.

[muttleypup]

Thats basically the issue I had, except it was the bottom pulley. You say you have a spare alternator so at least you can confirm if it’s that before spending out on a replacement

[ZsZ]

then just need to find the spare in the storage

[Oldiebut goodie]

Maybe you should be running a wider belt? Such as a 10 instead of a 9.5.

[ZsZ]

Maybe you should be running a wider belt? Such as a 10 instead of a 9.5.

I am not sure if that 0.5mm counts, but might work aswell.
Will check the current belt as lot of mislabeling occurs. Maybe the current one is 10mm wide.

Did find a cheap aftermarket pulley at different local webshops, just have to check the local parts store if they can have it quicker.
This is the manufacturers page: https://as-pl.com/en/p/AP0001

[ZsZ]

bought a new pulley for the alternator.
Now the belt slips at the water pump

[muttleypup]

Same issue as I had, new pulleys on the water pump sorted it. Maybe try a thicker belt as oldiebutgoodie suggested first? I got pulleys from Areacamper in Spain but depending on your setup you might find then local to you

[ZsZ]

OK it seems to be fixed.

On TheSamba Waldo adviced to turn the aternator with a socket and see if and where the belt slips or it turns the crank fine.
It was slipping on the water pump pulley on the crank-pump belt side.
I removed the pulley. It is not obviously worn, but has some marks.
I removed the shine form the belt surfaces with an emery cloth, assembled with one less shim and tested it. It was still chirping a bit so removed one more shim (I have now one shim on a new 9.5x630 belt) and it seems to be fine.
The belt is a bit too tight for my liking but still can turn it almost 90 degrees and push in a few mms, so it is probably fine.

I will try to find 10mm wide belts and get the pulley resurfaced on my Fathers lathe. It might be wise to check the crank pulley too.
Or move to a later setup with PK belt

Thanks for the help guys!