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Tue Apr 12, 2011 7:37 am

My generator/alt idiot light is no longer lighting up when I first turn the ignition key, I checked the light bulb it's fine, checked the fuses, I used my test light and got nothing...anyone have any suggestions. I am wondering if it's even worth the grief of trying to fix it.

Tue Apr 12, 2011 7:58 am

I'd feel uncomfortable leaving it like that. Maybe this link might help. http://www.vw-resource.com/warning_lights.html

Tue Apr 12, 2011 8:06 am

hank0306 wrote: I am wondering if it's even worth the grief of trying to fix it.

I think it is, because that light tells you if the belt is slipping or has broken while you're driving. If those things happen, the fan slows down or stops turning and your engine starts to overheat. When that light comes on while you're driving it's your signal to pull over and check things out. If it doesn't work you won't know your engine is overheating until you smell it and it starts to run badly.

Tue Apr 12, 2011 8:34 am

Check the blue wire at terminal 61 on the voltage regulator. Also check the brown ground wire from the voltage regulator to the generator.

Tue Apr 12, 2011 10:29 am

The generator, oil pressure and turn signal idiot lights all work on a similar principle. however, it is a bit backwards from normal, and if you don't understand it, it will be difficult to troubleshoot.

If you notice, all three bulbs mount in an insulated bulb holder on the back of the speedo. The outside conductor of these bulbs (contrary to what you might think) is not connected to ground, it is connected directly to switched ignition voltage, not via a fuse, so it will never be a blown fuse. Since the outside shell is powered by the ignition switch, if you ground the center or tip of the bulb connection, the light should come on.

In your case, use a test light to test for power on the edge of the bulb socket with the ignition switch on. If you get power here, then ground the center connection of the bulb to a convenient ground behind the dash. If the idiot light works, then the problem is more than likely in the rear, at the regulator, where the #61 terminal attaches to the regulator. Try taking the wire off there and grounding it to see if the idiot light works.

One clue - if, when you have the ignition on and the engine not running, both the oil pressure and generator lights should be on. If not, then you probably have a problem right there behind the speedo with power getting to the bulb holder. If only one of the lights is out, then it may be a bad bulb or a bad wire / connection in the rear. Also, if the generator has failed big-time or is not connected, the bulb circuit will not sense this and will stay out.

But by all means, do get the circuit working. This is your only line of defense to determine if the generator is working or not, or more critically, if you have broken a fan belt and then you may terminally overheat your engine without noticing it!

Just some hints...

Tue Apr 12, 2011 10:40 am

Thanks for all for the responses. Got it fixed, i miss wired it when I put the speedo back in....thanks again all for your quick and informative responses.