Alternator wiring question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Yukon Jack** · 11-01-2004, 05:47 PM

In the FAQ about switching from an externally regulated alternator to internally regulated http://207.44.196.117/vboard/showthread.php3?t=119379 it states:

Now the blue wire, which is just an extension of the brown wire, connects to the tab on the right (number 1 tab). The brown wire runs the the idiot light/gauge in the dash and is there for resistance to the internal voltage regulator. You can not skip this as it tells the regulator what it needs to be doing and when.

And it shows this pic

The engine I have put in the K20 uses an internally regulated alternator on the 1989 454. I am using Autometer gauges and am not using the stock wiring harness for the gauges. I won't have an idiot light like on a stock gauge setup. I'm concerned about the above info that says not to skip using the brown wire that is there for resistance to the internal voltage regulator.

Do I need to do something with the brown wire to tell the "regulator what it needs to be doing and when"?

Mixup · 11-01-2004, 06:03 PM

I had the same problem. I talked to Mark at M.A.D. and he said that you have to have a light so I put a little round indicator light under the dash and it works great.

**Yukon Jack** · 11-01-2004, 06:07 PM

Did you just find the wire in the under dash wiring and tap in there? Should be easy enough. Thanks!

**Yukon Jack** · 11-01-2004, 06:08 PM

Also, does it just light up if there is a charging problem or does it stay on all the time?

68w/sbc406 · 11-01-2004, 10:21 PM

i hacked my dash and stuffed a tach in where the idiot light is and changed over to an internally regulated alternator. i havent read the FAQ thing but i spliced 2 wires down on the regulator plug(the middle 2) and then put the new style conector on and it works fine. no problems

68w/sbc406 · 11-01-2004, 10:24 PM

Quote:

Originally Posted by Yukon Jack

Also, does it just light up if there is a charging problem or does it stay on all the time?

it should only light up when there is a problem. each side of the wire should have a current on it(even amount) and what causes it to light up is when one of the currents decreases then there is a difference in potiential. Or at least thats what i was told

**Yukon Jack** · 11-03-2004, 04:01 PM

So am I understanding that I take the brown wire and wire it so that it branchs into two wires and hook them to the feeds for an indicator light so it has power on both feeds?

11-01-2004, 05:47 PM	#1
Yukon Jack Post Whore Join Date: Feb 2000 Location: Rose Hill, KS, USA Posts: 12,684	Alternator wiring question In the FAQ about switching from an externally regulated alternator to internally regulated http://207.44.196.117/vboard/showthread.php3?t=119379 it states: Now the blue wire, which is just an extension of the brown wire, connects to the tab on the right (number 1 tab). The brown wire runs the the idiot light/gauge in the dash and is there for resistance to the internal voltage regulator. You can not skip this as it tells the regulator what it needs to be doing and when. And it shows this pic The engine I have put in the K20 uses an internally regulated alternator on the 1989 454. I am using Autometer gauges and am not using the stock wiring harness for the gauges. I won't have an idiot light like on a stock gauge setup. I'm concerned about the above info that says not to skip using the brown wire that is there for resistance to the internal voltage regulator. Do I need to do something with the brown wire to tell the "regulator what it needs to be doing and when"? __________________ 1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14

11-01-2004, 06:03 PM	#2
Mixup Registered User Join Date: Jan 2002 Location: Henderson, NV Posts: 358	Alternator wiring I had the same problem. I talked to Mark at M.A.D. and he said that you have to have a light so I put a little round indicator light under the dash and it works great. __________________ 1980 Chevy Shortbed Pickup 1969 Z28 engine Turbo 350

11-01-2004, 06:07 PM	#3
Yukon Jack Post Whore Join Date: Feb 2000 Location: Rose Hill, KS, USA Posts: 12,684	Did you just find the wire in the under dash wiring and tap in there? Should be easy enough. Thanks! __________________ 1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14

11-01-2004, 06:08 PM	#4
Yukon Jack Post Whore Join Date: Feb 2000 Location: Rose Hill, KS, USA Posts: 12,684	Also, does it just light up if there is a charging problem or does it stay on all the time? __________________ 1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14

11-01-2004, 10:21 PM	#5
68w/sbc406 Got Light Emitting Diode? Join Date: Apr 2004 Location: Newberg, OR Posts: 2,485	i hacked my dash and stuffed a tach in where the idiot light is and changed over to an internally regulated alternator. i havent read the FAQ thing but i spliced 2 wires down on the regulator plug(the middle 2) and then put the new style conector on and it works fine. no problems __________________ 1968 1/2 ton 2wd lwb 6 lug disc and bags up front. Next c notch and rear bags '02 Chevy Silverado LT ext cab short bed 2WD 5/7 drop on 22's(the family car) 1993 Cherokee work ride/weekend wheeler

11-03-2004, 04:01 PM	#7
Yukon Jack Post Whore Join Date: Feb 2000 Location: Rose Hill, KS, USA Posts: 12,684	So am I understanding that I take the brown wire and wire it so that it branchs into two wires and hook them to the feeds for an indicator light so it has power on both feeds? __________________ 1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14



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