Thought those who have installed or are going to install an American Auto Wiring (AAW) harness in their Tri-Five Chevy might be interested in the need for adding resistance to the brown alternator exciter wire in the AAW harness, especially with an early 90’s GM CS130 alternator. As an aside, I don’t have an idiot light in my install, and don’t get the resistance drop the light provides.
When I checked with AAW, Donny said, “we found out through lots of research that the CS alternators need a higher value resistor than what is in a stock harness of our Classic update kits. The brown wire already has a resistor on it, yes, but needs more. Without the higher value, you run the risk of damaging the regulator. That is why we led folks over to the other (SI) adapter. If you want to splice your own resistor in line, call the tech line and they should be able to give you the value of that resistor.”
I have a connection plug for the alternator, but there is no added resistance in the wiring. Turns out there are two connection plugs, one with added resistance, and one without.
When I called the AAW tech line, the tech told me the brown wire essentially had no resistance, and that I needed to add a resistor. He said he usually uses an 87 ohm resistor, but when I told him the GMPP installation manual calls for 50 ohms, he recommended adding that resistance.
Acardon wrote me: “If you look at the wiring diagram on sheet 3 : http://www.trifive.com/92965107 500435 IN 3.0.pdf You will see that the brown resistance wire (dashed line) from the accessory terminal, ties into the solid brown wire from the idiot light. This puts the light bulb and resistance wire in parallel, causing a drop in resistance, not added resistance. It's been my understanding that the extra resistance wire was a back up exciter for the alternator, in the event the bulb burned out or for voltmeter vehicles.
This is a pretty good article on the subject of converting to a CS alternator. http://www.novaresource.org/alternator.htm”.
Acardon had me measure the resistance from the accessory terminal of the ignition switch to the brown wire of the alternator plug with it unplugged, to isolate a measure of the resistance of the brown resistance wire. I measured 10.4 ohms, Don’s neighbor measured 10.5 ohms on his AAW harness.
As a result, I wired in a 50 ohm/5 watt resistor I had, in series with the brown resistance wire, yielding a total of 60 ohms of resistance. The novaresource post Acardon cited recommends between 35 and 350 ohms.
Thanks so much to Acardon, AAW’s Donny, and Roger1, for figuring this out.
When I checked with AAW, Donny said, “we found out through lots of research that the CS alternators need a higher value resistor than what is in a stock harness of our Classic update kits. The brown wire already has a resistor on it, yes, but needs more. Without the higher value, you run the risk of damaging the regulator. That is why we led folks over to the other (SI) adapter. If you want to splice your own resistor in line, call the tech line and they should be able to give you the value of that resistor.”
I have a connection plug for the alternator, but there is no added resistance in the wiring. Turns out there are two connection plugs, one with added resistance, and one without.
When I called the AAW tech line, the tech told me the brown wire essentially had no resistance, and that I needed to add a resistor. He said he usually uses an 87 ohm resistor, but when I told him the GMPP installation manual calls for 50 ohms, he recommended adding that resistance.
Acardon wrote me: “If you look at the wiring diagram on sheet 3 : http://www.trifive.com/92965107 500435 IN 3.0.pdf You will see that the brown resistance wire (dashed line) from the accessory terminal, ties into the solid brown wire from the idiot light. This puts the light bulb and resistance wire in parallel, causing a drop in resistance, not added resistance. It's been my understanding that the extra resistance wire was a back up exciter for the alternator, in the event the bulb burned out or for voltmeter vehicles.
This is a pretty good article on the subject of converting to a CS alternator. http://www.novaresource.org/alternator.htm”.
Acardon had me measure the resistance from the accessory terminal of the ignition switch to the brown wire of the alternator plug with it unplugged, to isolate a measure of the resistance of the brown resistance wire. I measured 10.4 ohms, Don’s neighbor measured 10.5 ohms on his AAW harness.
As a result, I wired in a 50 ohm/5 watt resistor I had, in series with the brown resistance wire, yielding a total of 60 ohms of resistance. The novaresource post Acardon cited recommends between 35 and 350 ohms.
Thanks so much to Acardon, AAW’s Donny, and Roger1, for figuring this out.