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Alternator Question

Posted: 25 Nov 2022, 15:04
by steveo9007
Ok, so every time i start my van and the voltage is low the Alternator squeals until it goes pass 14 volts or there about, my engine is the 1.7 Diesel, one belt covering the crank, water pump and Alternator, i have good voltage coming from the Alt, and my regulator is brand new.  When i tighten the tension on the belt i don't get the squel even when the voltage is low and its recharging the battery only after driving all summer and then sporadically through the quieter months do i get the squeal and then once it has the voltage it stops.

Voltmeter reads 14.3v when running, at idle around the 14volts mark. Alternator is 2 years old and is the 60 Amp one with a V belt which i have replaced also, i have checked if there is any movement on the pulley shaft and none. I dont know why it keeps loosing its tension or is that a thing with these vans, as when ever i retention it the squeal doesn't happen.  Anyone else had this happen to them and if so is there something i can do.  Would fitting 2 belts overcome this as i do have double pulleys on my crank and water pump ??

Re: Alternator Question

Posted: 25 Nov 2022, 15:13
by ZsZ
The glow plugs draw quite much current during post glow after the start.
Your alternator pulley probably polished up by squeaking a few times so it squeaks easier. May worth to sand blast it or resurface the V in a lathe

Re: Alternator Question

Posted: 25 Nov 2022, 15:22
by steveo9007
ZsZ wrote: 25 Nov 2022, 15:13 The glow plugs draw quite much current during post glow after the start.
Your alternator pulley probably polished up by squeaking a few times so it squeaks easier. May worth to sand blast it or resurface the V in a lathe

yeah its just annoying no matter how much i tighten up the belt, i dont have access to a lathe so cant really do that, would going to 2 belts take the strain off the alternator tension and keep it tensioned maybe ??
 

Re: Alternator Question

Posted: 25 Nov 2022, 15:37
by ZsZ
You may can sort the pulley with some emery cloth/sandpaper and elbow grease. If you remove the alternator you can turn the pulley by a drill and hold the sandpaper to remove the shine.
I am not sure why VW used the 2 belt system in the first but later they changed to the single belt - much easier to tighten that.
It is possible to switch over, but they use different pulleys both on the waterpump and the alternator.

Re: Alternator Question

Posted: 25 Nov 2022, 15:39
by steveo9007
ZsZ wrote: 25 Nov 2022, 15:37 You may can sort the pulley with some emery cloth/sandpaper and elbow grease. If you remove the alternator you can turn the pulley by a drill and hold the sandpaper to remove the shine.
I am not sure why VW used the 2 belt system in the first but later they changed to the single belt - much easier to tighten that.
It is possible to switch over, but they use different pulleys both on the waterpump and the alternator.

i have double pulleys on my crank and water pump only single on the alternator, but yes its easier to tighten with one belt, it just seems like the tension bolt slips no matter how tight it tighten it, shame it doesnt have similar belt to the 1Y and a spring tensioner

Re: Alternator Question

Posted: 25 Nov 2022, 17:33
by RogerT
Is it squealing on the alternator or the water pump? 14v might be a red herring and just coincidence with when your water pump frees off?

Re: Alternator Question

Posted: 25 Nov 2022, 18:07
by steveo9007
RogerT wrote: 25 Nov 2022, 17:33 Is it squealing on the alternator or the water pump? 14v might be a red herring and just coincidence with when your water pump frees off?

Defo on the alternator, I have had it all apart and check the WP and alternator pulleys, refitted with new belt and squeal, but as I say once it’s up to voltage the squeal goes, I point to alternator because it doesn’t do it when the battery is charged fully and belt tensioner, only when van has been sat for a week or so and no check on the tension of the belt, I drove away and above revs charging and over 14 volts no squeal.

Re: Alternator Question

Posted: 25 Nov 2022, 19:27
by Cecil
The belt is slipping when when the voltage is low because that is when the alternator is working hardest to try to raise the voltage.If you have a single belt but double pulley/pulleys does that result in the pulleys not being in accurate alignment and possibly causing rapid wear of the belt? My jx engined 1990 van has the single belt arrangement and I have noticed the belt wears quickly and needs frequent adjustment however it is easy to adjust compared to playing with shims to adjust the 2 belt arrangement. However I can see that the 2 belt arrangement may not slip so readily.

Re: Alternator Question

Posted: 25 Nov 2022, 19:35
by steveo9007
Cecil wrote: 25 Nov 2022, 19:27 The belt is slipping when when the voltage is low because that is when the alternator is working hardest to try to raise the voltage.If you have a single belt but double pulley/pulleys does that result in the pulleys not being in accurate alignment and possibly causing rapid wear of the belt? My jx engined 1990 van has the single belt arrangement and I have noticed the belt wears quickly and needs frequent adjustment however it is easy to adjust compared to playing with shims to adjust the 2 belt arrangement. However I can see that the 2 belt arrangement may not slip so readily.

Yeah that’s what I have to do adjust is more often than not, it’s just frustrating when it squeaks. I was looking at the ratchet bolt that the petrol engines have and seeing if I could bastardise the securing bolt of the tensioner maybe

Re: Alternator Question

Posted: 25 Nov 2022, 19:42
by tobydog
Try something the likes of:

https://www.gsfcarparts.com/982aa0690 ?

When I was a whipersnaper apprentice we had a block of stuff (it stank) to dress V belts. Stan the man used to give his Rover 100 a quick spray of 3in1 or similar to stop the dynamo belt sqealing....

Re: Alternator Question

Posted: 25 Nov 2022, 19:45
by steveo9007
tobydog wrote: 25 Nov 2022, 19:42 Try something the likes of:

https://www.gsfcarparts.com/982aa0690 ?

When I was a whipersnaper apprentice we had a block of stuff (it stank) to dress V belts. Stan the man used to give his Rover 100 a quick spray of 3in1 or similar to stop the dynamo belt sqealing....

Hmmm might get some of that and out it on a brand new belt see if anything changes. Cheers.

Re: Alternator Question

Posted: 25 Nov 2022, 19:49
by Cecil
I would be apprehensive about putting oil on the belt!
Belt dressing sounds worth a try!








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