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Alternator Brown Wire?

dwhess504

Well-Known Member
Alternator Brown Wire?*solved*

Ok Im having some charging issues and just finished reading a good thread by Kman on his issues. here is mine.

Not sure when it started could be after two possible events:

1. I was hooking up the boost guage light to the PRD21 Light so It could control dimming etc. Well in finding which was the hotwire two touched and I blew a fuse. replaced all lights seem to work.

2. I was test fitting the hotwire kit and when loosing the red wire from the back of the alternator the wrench touched the case and arced pretty good.

So I got the multimeter out and was at 12.5 with the engine off and no upswing in current with it running.

So today I replaced it with a Reman Alternator and have no change :furious:

I was reading that on Turbo buicks the Bat idiot light controls the brown wire. So I replaced every light in the dash.... no change (plus we dont have a bat light)

What Controls the brown wire? my thought is the alternator doesnt know to turn on.

Thanks!!

SOLVED!!!!!!!!!!.... kind of



Im going to get a Brand new Alternator, and Not even screw with the Hotwire Kit. I think it may be pulling to much amps or something and burning out the Alternator.

LATEST UPDATE: Got a New Duralast alternator and it is putting out 14+ volts! Screw the hotwire kit for now not even going to touch plug it in. and chance burning it up

Man what a freaking nightmare.!
 
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There is a 20 amp fuse that may have blown and caused the alternator to not charge. It is on the side closest to you when you open the fuse panel ch/fan. Check that and see if it's blown.
 
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I think everyone who owns a tta should purchase the service manual!

but im just a slow tawking southerner
 
I think the brown wire goes to the fan relay's... you have a SM so it will tell you if it's charging... it's also easy to disconnect the neg. bat. cable...
 
Yes, both low speed and high speed fan delays and also fuse box at c/h fan fuse 20 amp. 8a-30-1 TTA service manual supplement. Also alt voltage should be around 13.5 or so for the fuel pump performance. Check by scanmaster at idle. If you don't have a TTA service manual supplement you need to get one.
 
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The SM will read lower than what it's really doing but it will still tell you if it's charging...

X2

It seems the scanmaster can read .5v or more, lower than the multimeter. I had my rebuilder retest the fresh alternator, because of the scanmaster readings under heavy load (lights, ac, etc.). The alternator was fine, and on the high end of the specs.
 
well confirmed with voltmeter jumping the alternator "L" to 12v got it to output close to 14. So I have an issue somewhere. I guess it is the Relay since the fuse is good.
 
I checked voltage SM 13.8 at alt 14.2. What's really good is the autocraft silver battery has a date of 7/09 and is still doing great!
 
Man this sucks. Another day trying to find out why it is not charging. I put all brand new fuses in(none were blown).

-It will die without the neg on the battery.
-The alternator and bat read same thing with multimeter

I changed out this relay, thing just maybe , but nope
The fans come on with the A/C so that should rule out the fan relays right?

Only other thing I can possibly think of is I grounded the Hotwire kit in a bad spot... Longshot, but I will relocate it tomorrow.
 
unhooked it completely, didnt change. now Im really lost....

Could someone do me a favor and check the volts from the brown wire on the alternator. Now I know for Sure it has something to do with this
 
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From my previous posts, you could see I had all kinds of problems with mine after the hotwire kit. I never did pinpoint the cause, but I did buy a high output alternator and grounding kit and my problems went away.

These problems are no fun and make you worry about the car dieing on you when you are cruising...not a good feeling.
 
Do the fan's come on when it get's up to temp? what does the SM read while running? if you have the wrong wire grounded on the hotwire it could still feedback... even though it's unhooked at the alt...
 
My Brown wire reads the Battery Voltage with the ignition on.

Robert I am taking the hotwire kit completly out. Maybe conincidene, but my issues started when I started messing with putting the hotwire kit on.
 
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