Radio breakthrough, alternator, drive belt

[c.morewood]

I replaced the drive belt and pulley as they were squeaking, last weekend. Co incidentally I started getting alternator noise/breakthrough on the radio on FM.. I'd experienced it before on AM and LW but never on FM. It wasn't continuous but seemed to be getting worse.
Anyway today I took out the radio thinking that there might be a loose ariel connection.. but there wasn't. I also had a look at the radio facia as most of the lights have gone out and I wondered if the might be the same as the heater controls bulbs.. They weren't.. they are small LEDs. Ok so if I change the printed circuit board inside the facia, will I need another number password for the radio... in other words is the radio password needed for the radio case or the pcb?
Well result, after I'd reassembled the radio and put it back in .. no more breakthrough.. I'll leave it a week before I call it a success.
Now to the squeaking belt. Is it just the belt rubbing against one of the tensioners that has some dirt on it? Could it be the alternator bearings failing?
I gave everything a clean with gunk today and that stopped it for a while, but the squeak is back allbeit a little fainter..

[RichardW]

Not sure about the radio Chris - you can only try! Aftermarket ones are cheap enough anyway....

As to the squeaking, are you saying it's still squeaking? What did you change? There's the eccentric roller, and also the spring tensioner, either of which can be noisy. The other culprit is the crank pulley - any evidence of rust on the face, or running out of true?

[BX]

Over run clutch in alternator possibly seized, this is a very common problem in German vehicles. Also check the crankshaft pulley. The pulley may either rattle or cause a squeak in the belt. I haven't a clue as to what the radio problem might be.

[citroenxm]

Xantia Altinators dont have a PULLY CLutch..

Chris, Radio Codeing is stored on the radios MAIN PCB, so swapping the front for another will NOT alter the code what so ever, despite this, if its a Blaupunkt Series 1 radio then they can be easilly decoded from the BP code on the side of the unit with a small programe!!

[c.morewood]

I didn't change either the tensioner or the eccentric roller just the crank pulley.. so I guess they may be the culprits although they seemed to spin very freely when the belt was off. I was wonmdering if dirt in the grooves or what seemed to be a build up of rubber on the tensioner roller might be the cause? I've cleaned the buildup as best I can and whatever I did seemed to quieten things down .. its no longer "embarrassing driving through town", loud.
Paul, thanks for your help again.. so I'll get a replacement front pcb and hopefully that'll give me some lights.. a lot easier than trying to solder those diddly LEDs.

[qprdude]

They might not squeak when not under load Chris.

[c.morewood]

Driving in on the nightshift tonight and the breakthrough is back .. but interestingly all the radio lights and the clock light are now out.. back to square 1

[citroenxm]

Fiddle with the light dimmer on the steering Cowl?

[c.morewood]

No I think its maybe a loose connection behind the radio, the clock light went out after I put the radio back in, which maybe where the interference is coming from. definately not the dimmer as that works normally. I was reading a bad aerial earth could cause similar problems.. maybe its to do with the aerial and not the radio.. more investigation after the last night shift tonight.

[c.morewood]

Clock light is definately a loose connection.. thank goodness. PCB leds are all out but for one.. Does anyone know what voltage they might be? I've been looking at these ones
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... ink:top:en" onclick="window.open(this.href);return false;
But they'll be no good if the voltage is wrong.
Whe its dry there appears to be no interference which leads me to conclude that maybe there's a problem at the foot of the aerial.