Club 80-90 Forums

What's wrong with the alternator BTW ?

kevtherev wrote:What's wrong with the alternator BTW ?

Loud squealing when under electrical load, and prone to stopping if under said heavy load and idling at low revs. Belt changed, earths cleaned, new oilite starter bush.

E D I T Still delivering charge but you can tell the baby is under strain. Didn't help that I had the fridge running on 12v, headlights on and wipers at full speed

danmetallic wrote:

kevtherev wrote:What's wrong with the alternator BTW ?

Loud squealing when under electrical load, and prone to stopping if under said heavy load and idling at low revs. Belt changed, earths cleaned, new oilite starter bush.

E D I T Still delivering charge but you can tell the baby is under strain. Didn't help that I had the fridge running on 12v, headlights on and wipers at full speed

Doesn't sound like a new alternator is going to solve your problem. You put a new belt on - and, presumably, it's the right tension? But did you clean up and abrade the pulleys? If it's been slipping, then they'll be glazed. Is the lower pivot bracket bolted up properly and unbroken?

The alternator won't "stall" and stop the engine, if that's what you mean. That's a running issue, possibly throttle position switch, idle air valve etc, possibly just too low an idle speed.

AdrianC wrote:

danmetallic wrote:

kevtherev wrote:What's wrong with the alternator BTW ?

Loud squealing when under electrical load, and prone to stopping if under said heavy load and idling at low revs. Belt changed, earths cleaned, new oilite starter bush.

E D I T Still delivering charge but you can tell the baby is under strain. Didn't help that I had the fridge running on 12v, headlights on and wipers at full speed

Doesn't sound like a new alternator is going to solve your problem. You put a new belt on - and, presumably, it's the right tension? But did you clean up and abrade the pulleys? If it's been slipping, then they'll be glazed. Is the lower pivot bracket bolted up properly and unbroken?

The alternator won't "stall" and stop the engine, if that's what you mean. That's a running issue, possibly throttle position switch, idle air valve etc, possibly just too low an idle speed.

The alternator bearings under heavy load wouldn't do it no? Daylight running with no electrical strain and she's fine with minimal squealing. Yes, tension is fine and alternator is solid on mounts.

To be fair she hasn't stalled just revs have lowered when all electrics running.

danmetallic wrote:Yes, tension is fine and alternator is solid on mounts.

But did you clean and abrade the pulleys, and is the mount solid to the block?

To be fair she hasn't stalled just revs have lowered when all electrics running.

Which is exactly what you'd expect, because the alternator is putting a higher load on. The injection's idle control should resolve that, though, and keep the idle level.

AdrianC wrote:

danmetallic wrote:Yes, tension is fine and alternator is solid on mounts.

But did you clean and abrade the pulleys, and is the mount solid to the block?

To be fair she hasn't stalled just revs have lowered when all electrics running.

Which is exactly what you'd expect, because the alternator is putting a higher load on. The injection's idle control should resolve that, though, and keep the idle level.

I will take another look this evening and report back.

To be fair I'm only spouting what others had with similar symptoms

Thanks Adrian

My point is like Martins, that thing would be cheaper to get repaired.
£25 for new bearings up here
Is the spindle rough to move or is it smooth and free?

Is this too loose?
https://vimeo.com/109266586

I'm guessing so as it should be about 5mm yes?

Agreed looks like a 90A
these pics show the 90A vs 65A for late van with the m8 stud connection, note the squared section around the clamping screws on the rear casting, its rounded on the 65A

As said had mine rebuilt locally for £50

danmetallic wrote:I'm guessing so as it should be about 5mm yes?

Rough rule of thumb is 90deg of twist along the longest leg of the belt.

danmetallic wrote:I'm guessing so as it should be about 5mm yes?

I tighten mine to 1/2 an inch either way or 25mm in full

danmetallic wrote:I'm guessing so as it should be about 5mm yes?

Yes Mate....that's way too loose! this isn't a bike chain with slack, the belt actually needs tensioning, all the slack taking out and then further leverage to create belt tension.
I have read a few comments about 'over tensioning' and in my experience this is nearly impossible to do unless you are using a very long lever down the side of the alternator.
My preferred method is a large flat blade screw driver (about 14 inches) in between the mount and alternator body. A good bit of leverage to the right....hold the tension whilst nipping up the tensioner bolt.

Martin

I have killed two waterpumps, both went soon after tensioning the belt and were not old , I think I probably oved tensioned it so now I lean to the too loose than too tight side, you will know if it's too loose as it will squeal on startup, if it's too tight you won't know.