Alternator Workshop message

[sonyps23]

Hi, I've been getting this message on and off for about two years, it all started after I had the cam belt and water pump changed, I've done some research and tried a few thing but I've had the battery die on my twice within the last two/three months. I've changed the alternator and battery within the last two years, new alternator cable has been soldered both ends and just fitted a brand new battery junction box, but I'm still getting the message.

When I start the car the volts stay at around 12v and I get the message, if I rev the engine the message goes and the volts go up to 13-14v.

What else can I do?

Thanks

[insanitybeard]

If you've renewed all the likely items that could cause such a problem- the alternator itself, the battery, the charging lead connecting the alternator to the battery junction box and the battery junction box itself then you've covered the usual suspects for causing these kind of problems. I take it you renewed the alternator after the problem began to try to cure it? Is the alternator drive belt all ok and properly tensioned? No possibility that a defective freewheel pulley on the alternator itself is preventing the alternator shaft from spinning properly?

If you've done all of the above and you say the problem only began after a cambelt change then I can only think in the process of jacking/lowering the engine to do that job, the wiring has been strained or damaged somewhere to the (3 pin?) multiplug that connects to the alternator- I think these wires are responsible for controlling (via the regulator unit in the alternator) the alternator charging rate and output to the battery.

[Galaxy130]

prob a long shot but I got this warning message after driving through puddles. I am missing the undertray and the water splashes onto the belt and makes it slip . Happens mostly in places like gravel yards with potholes filled with water at slow speed rather than normal driving.

[sonyps23]

Thanks for the replies, yeah all thing been replaced with the alternator being first after the cam belt change, I took the first alternator back as was still getting the message but the second one was the same, I've read about the alternator pulley before but not 100% how to test/check it?

Undertray in place and no puddles.

Cheers

[Chrispb]

Did your new alternator not come with a new pulley attached?

To test the clutch in the pulley whilst still on the car.

Release the drive belt from the alternator, locate the fan blade through the slots in the alternator casing, now carefully place a screwdriver through the slot to contact the fan blade.
Now while preventing the fan blade turning try turning the pulley.
You should be able to turn the pulley anticlockwise with little resistance but you shouldn't be able to turn it clockwise at all.

Normally these pulleys seize and there is no free wheeling action.

Possibly in your case the pulley is free wheeling both ways.

[sonyps23]

Yes it was already fitted, I'll give it ago at the weekend hopefully, thanks.

[Mirez]

Sounds like a problem with the excite circuit. With the ignition on (engine NOT running) measure the voltages on the small two pin plug at the alternator.

[sonyps23]

Pulley clutch is ok, the voltage on the plug was 11.8 on the alternator and 12.4 in the plug on the on of the wire, if that makes sense! Is that good or bad?

[sonyps23]

Now fixed!! Car broke down just before Xmas and AA man said it was a dodgy alternator, which I thought was strange as it was new two years ago. Anyway started to look online for new one, saw cheap brand new ones called RTX so checked them out but soon found out they are cheap for a reason, anyway found a recon one on eBay for Ã,£80 and it works perfectly, and guess what make my old one was...yes an RTX one!! So don't buy RTX alterators!