View Full Version : Ignition light on after generator replace

09-20-2010, 08:24 PM
My regulator took a crap and caused my generator to nuke recently. Today I fired it up for the first time after having the generator rebuilt and a new regulator. I set it to negative ground with arcing the "A" terminal to the "F" terminal. I fired it up, and it bitched and moaned, but it fired up (been sitting for about 5 weeks). The ignition light initially was not on, then came on. And it stayed on. Now, the regulator is a new one from Moss, got it from my local guy who had it sitting on his shelf for a few years. The wiring harness is new, so I suspect no problems there. Any thoughts?

09-21-2010, 08:42 AM
I just dealt with this, but I am not sure if your situation is the same as mine. When you say the light stays on, do you mean while the key is still turned off or while the car is running?

09-21-2010, 09:21 AM
Light should be on when key is on and engine not running or running slowly.
As engine speed increases light should dim and then go out all between maybe 800 and 1500 RPM.

09-21-2010, 09:32 AM
Well my lights isn't going out. Does the generator and regulator need to function for a bit, kind of settle in, before it starts charging right?

09-21-2010, 09:42 AM
Think not. It is the regulator. Something wrong in there, that is if the generator is indeed working.

The light is to tell you that the generator is not generating.

I think I would check the generator output, any auto store can do that if you can not. Oh yea, no charge for that.

09-22-2010, 07:51 PM
It should start charging right away and stay that way.

First, recheck all connections. We had a similar case recently where the owner left the ground off the regulator. That'll do it!

You can check the generator by disconnecting both wires, then connect a jumper from the field to the output. Start the car and don't let it go too fast--you should easily get 20V at the connection, as you GRADUALLY increase the engine speed. Don't let it get higher.

Probably not the control box. Wouldn't be the first time a generator failed after being rebuilt.

09-23-2010, 10:22 AM
I just had the generator checked, and it is working fine. There was a good amount of paint on the bolt areas, so I took a wire wheel to them and got it down to bare metal. Maybe the generator wasn't grounding because of that? I will finish installing it tomorrow and see if that helped.

09-23-2010, 11:38 AM
Hmm, no idea. Never thought about it being grounded through the attaching bolts.

09-23-2010, 09:58 PM
If its been sitting for quite a while try cleaning the contacts in the regulator with some 'wet or dry' paper. If that does'nt do it you may have a bad regulator or you may need to clean some wiring connection's with spray contact cleaner.


09-23-2010, 11:02 PM
Question for ya'll, I just fired it up and still not charging correctly, but I noticed that I can't find any ground going from the engine block to chassis. Is there supposed to be one somewhere?
If the regulator, which is new, is bad, what's a quick and effective way to determine if its bad?

09-24-2010, 07:34 AM
You will have the same voltage reading with the car running at the battery, voltage regulator input and output spade

Your voltage reading will be below 12.3 volts. Most likely 11.8 since your battery is not receiving any voltage increase from regulator. This amount will slowly be demised from draw of igniton system

09-24-2010, 07:01 PM
The traditional location for the engine-chassis ground cable is under the car, from a bellhousing bolt to the chassis. You probably can't see it from above. But if you can start the car, you've got a connection somewhere. Still, if there isn't a heavy cable, you really should put one on.

Yes, you need clean connections at the generator mounting tabs, because that's the generator's ground connections. It's pretty hard to get this wrong, though.

The operation of the ignition light is pretty simple: it is connected from switched 12V (which also powers the ignition and almost everything else) to the generator output. So, the only thing that can turn it on is no generator output or some kind of miswiring. I suppose it's possible that the problem is in the box, but not likely. Make sure that the field connection (F at the box, small wire going to the generator) is OK. Make sure you haven't accidentally switched the field (F) and output (D) connections at the generator. This is hard to do, as they're different-sized tabs, but I suppose it's possible. Also check for voltage at the field terminal when the car is running. Maybe it's disconnected somehow in the control box or miswired.

My guess is that it will be one of those slap the forehead, geez-how-could-I-have-done-that kinds of things.

09-26-2010, 08:58 AM
Did you polarize your generator? If it has been sitting for a while this may be the problem?

09-26-2010, 02:28 PM
Yes, I polarized it.