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Discussion Starter #1
I can not find short, I have a constant draw on battery & gen light on at idle, have replaced w/100 amp alt., under hood wiring harness, regulator, battery and about to replace horn relay. Only aftermarket installations are radio and tach, car has no a/c or other options. anyone had similar problems or ideas ?
 

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Are you sure that there is a short or draw on the battery? A problem like that usually occurs when the car is off. The problem ends up to be a dead battery. Just a couple of questions.
It sounds like your concern is the GEN light being on at idle.
Does it go out when the car is going down the road?
Did this occur before you changed out the alternator?
Did you put a 1-wire 100 amp alternator in there or is this an upgraded GM 3-wire internally regulated alternator?
When you did the upgrade, are the regulator blue and brown tied together?
Are they still tied to the regulator or are they just joined together?
 

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Discussion Starter #3
Let me start from the begining, having sat most of the winter and thinking it was just a dead battery I made the mistake of trying to jump it instead of a slow charge, this fried the wiring harness. I took a harness out of a 67 and installed it, I purchased a 100 amp alt. (3 wire-white & blue on plug and red hot) I also installed a new external voltage regulator, new battery, and new selenoid & starter thinking I covered all the bases, I did not, the generator light will come on at idle and go off as I rev the rpms, and if I do not use the kill switch the battery eventually dies.
 

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I'm assuming the car is idling at the right RRM and the alternator pulley is the standard size. If so:
See if the alternator is putting out the proper voltage.
1, Measure the output on the red wire while the car is idling and the gen light is on. Measure to a good ground. Guessing that the voltage will be below 13.5. Post that reading.
2, Measure the output of the alternator blue while the car is idling and the gen light is on. Measure to a good ground. Post that reading.
3, Repeat the above 2 steps while increasing the RPM a little so the gen light goes off. The output of the red wire should go up.
Not sure at this point if the alternator is acting up or it isn't regulating properly without first measuring things.
Had a similar problem on my 64 with a new alternator & regulator. Got is to regulate better and stop the battery draining problem by changing the new regulator. That would be my first thing to try because it's quick to try. I put in a Wells solid state VR715. Somewhere around $12.00 at AutoZone. Disconnect the battery before installing. Be sure to ground the regulator case to the core support. Either with a solid bolt through one of its feet or with a separate ground strap.
Comment:
You do have a ground wire from the battery negative to the right inside fender?
 

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Discussion Starter #5
I think I found the problem, while installing new voltage reg. I noticed a broken prong on the harness plug. Temporarly
fixed ( until I can find a new plug for the volt. reg. for a 66) and so far seems to be working good. Thanks for all your help.
 

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The plug doesn't need to come from a 66. Find just about any Chevy (GM) with a external voltage regulator. Find a decent plug and cut it off. Solder and shrink tube the joints. Shrink tubing is available at Radio Shack or Home Depot.
*EDIT*
I used your word "plug". What I meant was to cut off the entire V/R connector and replace it. Typing without thinking on my part.

[This message has been edited by John_Muha (edited 04-30-2002).]
 
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