Can a loose fan/aux belt

[stu9]

Cause dim lights, slow turning trying to start ect....just wondered

[DickieG]

Cause dim lights, slow turning trying to start ect....just wondered

Yes because the alternator won't be spinning at the correct speed to provide sufficient charge to the battery and other electric items.

[stu9]

Cheers, oh well a new one and tentioner are required then

[Xaccers]

If the tensioner has a spring behind the hydraulic pump then it is best to replace that too

[stu9]

I'll get what I need

[red_dwarfers]

The common failure point on the spring damper thing Stu are the holes at either end elongating. The spring itself should be very hard to push.
If you don't have air con you'll just have the much simplar manual tensioner setup which usually takes half the time to fit!

[stu9]

Ok thanks, I do have it (a/c.....not I ever bloody use it, as you dont need it this country!).....I was told I need the make of alt as there's 2 sizes of belts

[red_dwarfers]

The way I tend to do it is turn the engine with a socket on the crankshaft pulley until I can see the length markings on the belt. Usually in the layout of 6PK1234 if I remember correctly. That is of course if that hasn't rubbed off. If it has rubbed off I remove the belt and take it down to my local motor factors for them to match up. Usually you can be a little flexible with lengths by a mm or 2 if the factors don't have the exact one on the shelf as the slack can be taken up in the tensioner.

The proper way to do it of course is to find out the make of the compressor, I've no idea how to identify it on the car though!

[stu9]

Thanks for that

Can a competent diy'er do it

[red_dwarfers]

Most certainly. As with anything there can be catches but more often than not it's a straightforward job. Jim did a guide on replacing the tensioner, here it is.

[RichardW]

It's a C5 Hdi - the belt arrangement is different to the one on the Xantia TD. If it was slipping enough to cause a voltage drop it would also be squealing like a banshee - there'd be no doubt about it.

[red_dwarfers]

Haha! Brilliant! Thanks Richard. You probably should ignore most if not all of my posts above, I had my single track Xantia/XM hat on!

It would be worth noting down the car and engine in your signature so it doesn't happen again.

[Peter.N.]

Connect a voltmeter across your battery with the engine running it should read about 14.4 volts, much less and your alternator is faulty, if it reads OK could be your battery.

Peter