Generator Light, school me on normalcy Options

[stepuptotheMike]

So I took the car out this evening to stretch her legs good before the long trek up for ECC2008.

As I was getting back it was after dark and I noticed a faint (very faint) glow from the generator light. Now I had everything running.... Lights, Fogs, Fan, stereo. If I hit the turn signal, I could notice the slightest pulse in the light along with the signal.

Is this normal? Never noticed the G light coming on at all before... but I don't really drive the car at night very much either.

Alternator belt appears to be tight enough. Battery registers 12V at the poles. I've cleaned the ground points on the car several weeks back (both headlights, tranny strap, neg battery terminal).

The car ran really well this evening, so I think it did some good to get a longer trip under it's belt. Just trying to establish normal from abnormal.

Thanks,

Mike

[r_towle]

Its not normal to see the light, dim or not.

Try this.
remove and clean all the fuses (higher current draw)
remove and clean the Voltage regulator with electronic cleaning spray...clean the little connectors.
remove and clean the positive lead that attaches to the starter and alternator at the starter post (underneath where its all grimy)
clean the back up lights while you are there.
Clean all the tail ligh connectors.

If you are running all your lights etc and all of the connections above are dirty, you will be drawing more amps then the alternator produces....thus the dim light will come on.

Rich

[markb]

You might also go thru & clean all the grounds (don't forget the trans strap).

[gasman]

Hey Mike.....If you were at idle and the light was dim, I would think you are ok... But if you were driving down the road and with engine rpm's high, I would think there is a problem. Check your charging system at idle and see what the volts are at the battery...I think it should be between 13 and 14 volts...Put a draw on the battery...(lights fan etc...) There should be no more than a 1 volt drop....well that the way it used to be in the 1970's....Make sure your battery has water above the plates...also check you individual cells in the battery...could have a dead cell. Maybe auto zone will do a load test to make sure the battery is ok....also check the belt...when you have a draw on the charging system, it puts a strain on the belt too....Thats why you can hear engines slow down when you start to put all the electrical things on in your car...this might cause the belt to slip....and another thing you can do is....don't drive at night.....let me know if your going to Octoberfest Oct 11 in Greensboro...PCA only..Take care...Jim

[stepuptotheMike]

Hey Jim,

Sorry I hadn't gotten back to you on your email. It's been CRAZY with work over the past 2 weeks and I've been trying to get the car ready for ECC this weekend. I don't think I'm going to make Octoberfest.

So here's what I've done/noticed so far:

1. Pulled all the fuses, clean as a whistle.
2. Measured the voltage at the battery with the car off = 12V
3. Measured the voltage at the battery with the car running and no accessories = 13.5V
4. Measured the voltage with car running and lots of stuff on = 10v - 11v
5. If I rev the car, while all the stuff is on, the voltage read at the battery goes up to ~12V.
6. Alternator belt i would say has about 1/2inch of flex on it....which I wouldn't call loose, but you tell me.


The following grounds have been cleaned on the car:
1. Left headlight
2. Right headlight
3. Transmission Strap to body
4. Negative battery terminal to body. (actually replaced the cable)
5. Cleaned the ground wire connections on the tail lights (brown wires).


Still need to try:
1. Clean voltage regulator contacts
2. Clean the + lead at the starter post... will have to try that tomorrow.

Any other suggestions are welcome and thanks for those so far.

-Mike

[davep]

Normal battery voltage, engine off, is 12.8 volts at the posts. If it drops below this with the engine running, and a load on the system, then the alternator is not doing its job.

[AvalonFal]

See Tech Tip 545 on page 210 of the the AA catalogue - alternator diode.

Paul

[gasman]

Mike...It seems like you covered all the bases except actually getting into the alternator. As I is see it, You are ok...The battery is being charged. You would only have a problem if you sit in traffic for a long period of time with some accessories on. I think the above answer is more like your problem. That light is connected to th alternator diode. As for now, Have a great trip and worry about getting gas.....Jim

[r_towle]

Clean the VR and the positive lead on the starter...
The starter lead goes to the alternator...and its under the car and covered in crud.

Rich

[markb]

There's a ground next to the fuse box, and one under the relay board. These are grounds for multiple things, so should be checked. There is also a ground on top of the block for the engine harness.