My 68 Camaro generator light has now starting coming on when I turn the switch "OFF". It goes "out" when I start the car and stays off until I turn off the ignition. I did have an old battery, so I replaced it with a new one. But the generator light still comes on when I turn the switch "OFF". WEIRD !! Anyone have any clues why the generator light would stay on with the switch off ?? It has a new external voltage regulator and rebuilt alternator that was completely gone through, both about a year ago and have had no problems until today when I started out to the car show. Of course I am getting ready to sell the car, and now this !!! Thanks for any ideas...
Kim
olecarman@charter.net

Possible bad Diode in Alternator or Contacts in the Regulator. Might be the Ignition Switch or something weird happening around the Horn Relay?

won't be the horn relay or the ignition swtich, regulator or alternator.

If the Gen Light is only suppose to ground and Light when the Ignition Switch in in the run position and assuming the Ignition Switch is OK, would the Starter or Alternator Field Winding Grounding Out cause this to happen?

Ya know, I think you are right...

The gen light gets 12 volts from the ignition switch. It gets 12 volts or no volts from the regulator.

Without the 12 volts from the ignition switch, the gen light cannot light.

yup, you were right, "weird"

Guys I will say this. The ignition switch is the original switch and the key is starting to wobble around a little like the switch like it may be wearing out. So where should I start ?? Switch ?? Generator ?? Regulator ?? I have another generator I could put on it.
Thanks
Kim
olecarman@charter.net

Ignition Switch would be my first look - blow it out and spray some Rust Check in it - if it doesn't fix it buy a new one - It's been a Weird diagnoses :o))

Is the light on bright or dim? Try wiggling the key with it in the off position, to see if it goes out. Have you did any recent wiring? Try disconnecting alt and VR plugs to see if it goes out. If disconnecting VR plug and it goes out, test for voltage on terminal 4 at VR and the brown wire. If there is power on terminal 4, then VR is bad. If there is power on brown, then possible IGN switch is bad, or a backfeeding issue from wiring something.

This is a weird one.

Greg, it just can't be at the regulator / alternator end. That line would normally be "low" with the car off, that's why the gen light lights in the "accessory" position of the key.

Is it possible you're going all the way to accessory?
Sometimes when these switches get old, the key will come out there.
Is the radio or anything else staying on?

Let’s do a retake on this or just me thinking out loud. – lol. When the key is in RUN Position, motor running and alternator turning over there is 12 Volts feed form both the VR Brown wire and from the Ignition SX to the light Bulb which will not light as the opposing 12v cancel out. Providing the Ignition key is in the Run Position and supplying 12v, the only way for the Bulb to light is for the 12v from the VR’s Brown wire to stop, thus upsetting the 12v balance and current would then flow from the Ignition SX through the bulb and back through the brown wire and probably grounding through the VR. If removing the Key does not open the 12v feed to the bulb the light would remain on. I believe it is an Ignition SX problem. Greg points out that if the VR is bad it might be feeding current from the battery to the bulb but where would it find ground to light it?

On the other hand Jim might just have the magic answer but he chooses the Ignition SX as well - lol
Very interesting Problem – Don’t forget to keep us posted and Good Luck :o))

I appreciate the information. I will be experimenting with this Monday or Tuesday. I got the battery disconnected right now, so no problems there.
I haven't done any recent rewiring to anything except to replace a console bulb that went out. Thats it. I did put in a new 350 Turbo transmission a few weeks back, but I wouldn't think that would have done anything.?
I'm kind of leaning toward the ignition switch, but we will see in a couple of days. I will let you guys know what I find out. This one threw me a curve ball for sure...
Thanks for all your help.
Kim
olecarman@charter.net

OK Guys. I unplugged the generator and the light stayed on.

I unplugged the voltage regulator, and the light went out.

Does that mean I need a new voltage regulator or is it between the switch and the regulator ??

Thanks
kim
olecarman@charter.net

Sounds like a bad regulator. If it was mine, I'd replace both the alternator and the regulator with a new internally-regulated alternator. http://www.camaros.net/techref/ftecref14.html

I unplugged the voltage regulator, and the light went out.

Does that mean I need a new voltage regulator or is it between the switch and the regulator ??

Thanks
kim
olecarman@charter.net

Maybe, maybe not, did you do these tests
If disconnecting VR plug and it goes out, test for voltage on terminal 4 at VR and the brown wire. If there is power on terminal 4, then VR is bad. If there is power on brown, then possible IGN switch is bad, or a backfeeding issue from wiring something.
Also check to make sure the regulator body is well grounded to the rad support, and you have the small wire from battery negative to the fender. You can also test the brown wire by, grounding it to bare metal with the key off, the GEN light should not come on. Post back.

Sounds like a bad regulator. If it was mine, I'd replace both the alternator and the regulator with a new internally-regulated alternator. http://www.camaros.net/techref/ftecref14.html

Thats what I always did if anything with the external system needed replacing.

Had the same problem on my 69 , Light would come on with key in Off position, Changed Horn Relay same thing, Changed Regulator same thing, Changed Ignition Hookup down on the steering Colum same thing, was then thinking a short in the wiring, off to Elect Shop, $159 later New Alternator installed No more light., Funny thing is the Alt would Charge Fine only battery drain was the light when the key was turned off.

I say bad ignition switch. Drop the switch and see what terminals on the rear are still getting power after the key is off. You can go to a local Autozone and buy a new switch for about $30.00 bucks. Yes they have them in stock :)


Kev

Funny thing is the Alt would Charge Fine only battery drain was the light when the key was turned off.

I bet you had 1 burnt diode and was charging say 1.5 volts less.

But I say it's the Ignition SX in this case - When will we find Out - LOL