TheSamba.com :: View topic - Red Generator Light Suddenly On after messing!

Fri Jul 04, 2008 6:53 pm

Today I fitted a new working clock to my 1969 Fastback.

I also fitted a dashpad and so had to disconnect the cluster of warning lights under the fuel guage.

Since putting everything back together I now have a generator light showing permanently.

The car has been recently serviced so I am pretty sure it isnt oil (eg if I put the cables back the wrong way around). Is it possible that the generator is not providing enough current now the clock is running? Would that cause the light to show?

I do know that the brushes need replacing but it was working fine this morning before I fitted the clock and dash so I doubt they have suddenly disintegrated. I did have the lights on and off for a while to check which connections were which.

Any suggestions?

Thanks
Rob.

Fri Jul 04, 2008 8:05 pm

Go to the voltage regulator and disconnect the terminal 61 - the blue wire. Then start the engine and see if that light is still on. With that wire disconnected, there should be no way for the light to come on, and if it is, you've gone and shorted that wire somewhere, and that's the reason for the light.

-Andy

Sat Jul 05, 2008 11:37 am

Is the voltage regulator under the seat or attached to the generator?

What is the easiest way to check the generator is working?

Sat Jul 05, 2008 11:47 am

T-3's have it under the seat on the left side.

Sat Jul 05, 2008 12:19 pm

robburns1 wrote:
What is the easiest way to check the generator is working?

Go here for a good site about generators:

http://www.nls.net/mp/volks/htm/gen.htm

Basically you'll find two tests, one where you ground the field (DF) out and then start the engine and check for voltage, this is a brief test as when you rev it up the generator will quickly shoot way up in voltage.

The other test is to polarize/motor the generator. Remove the generator belt and on a type 3, I'd take off the rest of the adjusting shims or just put the pulley back on without the belt, and do the polarization procedure. That's where you unhook the D+ and DF wires from the regulator, ground the DF and put D+ to battery positive, this turns the generator into a motor and it should spin in the correct direction. If it goes the other way - not likely but I've seen it - you need to grab the pulley and spin it the other way til it moves in that direction on its own. This is also a brief test.
-Andy

Sat Jul 05, 2008 4:02 pm

Ok, well thanks to that little pointer I realised it is the Oil Pressure light that is on.

I will have a search now through the forums but does anybody have any suggestions as to what I might have done or for remedial action. I will check the oil but as I said the pressure was fine before I messed about with the wiring and even on the one occasion when I ran low on oil the light only came on around corners. Finally as I said it was serviced 2 weeks ago and doesnt usually lose a drop.

Sat Jul 05, 2008 10:40 pm

Well, same thing, disconnect the oil pressure warning light switch on the engine and see if the light stays on or goes off. If it stays on with the wire unhooked, then you have wiring issues. If it goes out, then you have engine issues.

Sun Jul 06, 2008 8:48 am

Yep. Spot on. I then ran a cable from the switch to the light and it came on then went off. Turned out that the correct cable was down in the depths of the dash. Sadly a bad spray job mean that much of the color coding was lost years ago so most wires are the same blue as the car.

Still nice to have it sorted and thank you for your assistance.