Alternator charge light peculiarity/problem.

[Slim]

Okay... even an electard like me can manage that kind of basic instructions. I shall go home at lunchtime and do that.

[ScreamingHeap]

Haha all good man, if it does not light up when you ground that wire the lamp is wired incorrectly and I can tell you how to sort that really easily.

[timbosaurus]

Yeah, all good ideas, and yes, all the normal checks were done and the light does comes on when that wire is grounded.

The wiring is as described above, and is new. The problem is not as simple as that. The problem is that the L terminal does not behave as expected, and slim and I are wordering if anyone knows any reason why industrial alternator outputs would be any different. If not, then there is something up with the alternator.

[timbosaurus]

And IIRC the L output does not give 12v at ign on, and ground when charging, so it's not as easy as changing the other lamp pin to ground instead of ign.

[Slim]

So, should i not bother going home at lunchtime Timbro? You already checked that?

[ScreamingHeap]

I have looked at the Alt spec and its 12v internal reg etc etc normal direction rotator, so nothing to trip you up there, regulator out is definitely on L pin so if its wired correctly I suggest you take it to an auto sparky and have it looked at. Its a forklift Alt in case you were ever interested. haha

[Slim]

Probably cheaper to get me another one than go to an auto-elec. The bloke that i got it from has access to another 4, for cheap.

[timbosaurus]

Can we 'borrow' one slim?

[Slim]

I shall find out.

[midnight_purple_GA70]

the way it should be working is

L should get 0v output from the alternator when the ignition is ON
when it is charging the L pin should get 12v

the light in the dash should get 12v ignition on one side of it
the other side goes to the L pin of the alternator

when the alternator is charging there is 12v going to both sides
when it is not charging the alternator should ground the L wire and the light should be on...

as someone said earlier you might have a blown fuse or a short in the ignition side of the charge light under the dash (not directly related to the alternator
so with the ignition on the alternator is grounding
the other side of the charge lamp is grounding also therefore it does not turn on...

however when you start the car the L wire outputs 12v which would normally balance both sides of the light at 12v and turn it off however if the ignition side is grounding then the light will turn on while charging...

[timbosaurus]

Yup, thats exactly how it should work, but it doesn't.

'L' terminal is open circuit and floating at around 1v when ign is on, and grounded when alt is charging.

[Sam_Q]

Can we 'borrow' one slim?

sure can, I have a whole pile of them now. They are originally for a general purpose stationary engine.

Now to hijack the thread anyone know how I can find out the max rpm of one of these?

[timbosaurus]

Do u want the obvious way or the safe way... lol.

[Sam_Q]

hahahah well I need to be able to sell them with a kit so saying 'oh it might fry/seize or something' might be a little unprofessional!

[Slim]

Well, you sold me one without that information.