Possible alternator issue??

[Waddock]

Hi all.

I have been using the Rex for the last few days to a from work whilst the snow has been out.... it has been great fun :wiggle

However today I had a major problem. There was a burning smell and bit of smoke from under the bonnet.. So with a fire extinguisher in one hand I had a quick look thinking the worst had happened! The smoke appeared to be coming from my alternator. So I left it to cool down and it stopped smoking. I thought it was damp from water splashing up so I got back in the car and drove straight home. On route I watched the battery voltage meter on the PFC, slowly it went from 12v to 8v only picking up at 4000 rpm to 10v. The battery is new, only replaced in October 2008 and still has warranty. When the RPM dropped power was down to 8v which caused the car to splutter a bit.

It sounds like I have killed the alternator. But this does not explain why the voltage does rise with the RPM? Does any one know of any other surrounding parts that could be faulty and cause this symptom? I read in one thread that part of the alternator could fail and thus still provide some charge.

I am now charging the battery backup so I can perform some tests. Maybe something is drawing more power than the alternator can supply hence why it got so hot trying to provide power?

If not I guess I will be needing an alternator so if anyone has a spare or is breaking a car for parts please PM me your price.

I really want to get this working again ASAP as I have refound my love of the REX and don't want to stop driving it!

Thanks
Ben

[D2BBA]

Sounds daft mate but have you checked your belt isnt knackered?

Failing that is it the pulley that has gone.

My airpump went the other year and did the same to the belt and PS pump just went and took out the other belt, lol!

Chris

[Waddock]

It is a new belt, but my air pump did seem a bit noiser than normal. How do I find out if it is broken?

[Waddock]

Thinking about it.... why did the alternator smoke up?? Must be faulty??

[pdtaylor18]

The alternator is just a glorified motor with lots of windings, if they start to break down then all that current produced will arc across somewhere inside. Alternators are notorious for collecting dirt etc and this is what can cause the arc tracking or fire. I would seriously though get rid of the alternator if you can proove its this as the cause. The last thing you want is a fire anywhere under the bonnet of a rotary.
Alternators should kick out around 14V if not more and battery should be 12v or so statically but with engine running this will go up a bit. (only a rough guide)

[Waddock]

I think you are right.... no more driving until I fit a new one... Its not worth the risk to the beast!

Anyone have a good one for sale?

Ben