Diode install

[falconvan]

I'm getting some kind of feedback through the ignition circuit since I put this GM alternator on. The truck wont shut off with the key, you have to pull a wire off of the ballast resistor to shut it down. An article I read said that in this case, a diode needs to be installed but it wasn't real clear on where or what kind. Anybody had this problem?

[Don Coatney]

It sounds like you are back feeding alternator output current through another wire connected to the ignition side of the ignition switch. How did you wire in the alternator?

[falconvan]

#1 terminal to ignition, #2 terminal jumpered to battery post on back of alternator.

[Don Coatney]

#1 terminal to ignition, .

There is your problem. Should be wired to the battery wire that was on your regulator. Not to the ignition switch.

[falconvan]

The old wiring is all long gone; I'm wiring from scratch. What do you do in the case of an internally regulated alternator?

[Don Coatney]

The heavy output wire from your alternator should connect to the battery

wire on the regulator or in the absence of this wire it should connect to the

back (input side) of the ammeater.

[teardrop puller]

check out this site.

http://www.madelectrical.com/catalog/alt-1.shtml

kai

[greg g]

You can use a small light bulb in place of the diode. The bulb will have enough resistance to prevent the back feed and allow the key to shut off the engine. It can also be an indicator to let you know you ignition circuit is in.

Just get a socket for an inline bulb, that is has two wires on for feed and one for ground. A GM side marker light is a good doner. Then splice it into the line you have running from igniton to the alt. The bulb will pass current to energize the alternator, but on shut off will not allow current from the alt to backflow the ignition circuit. If it works you can leave it or you can put the diode in the same location with the same effect. If you leave the light an make it visible. just remember, it is not an altenator light in the sense of the stock idiot light, just the opposite.

[Jims50chrysler]

I think speedway motors sells a unit that you install to prevent the engine from running when you shut the ignition off when you use a GM alternator

http://www.speedwaymotors.com/p/2373,262_Alternator-Wiring-Harness.html

Jim

[falconvan]

I think speedway motors sells a unit that you install to prevent the engine from running when you shut the ignition off when you use a GM alternator

http://www.speedwaymotors.com/p/2373,262_Alternator-Wiring-Harness.html

Jim

I called them; this is exactly what I needed. Thanks, Jim! I ordered it today.

[mikehalek]

Don, where did you find the electrical diagram?

[Don Coatney]

Don, where did you find the electrical diagram?

I have had it in my Photobucket album for a long time. I dont recall exactly where I got it but it was on the internet somewhere.

[randroid]

Don,

Are the wire numbers in the diagram their guage?

-Randy

[Don Coatney]

Don,

Are the wire numbers in the diagram their guage?

-Randy

Randy;

I believe that is the wire sizes.

[Merle Coggins]

Yes, the numbers refer to the wire gauge. That diagram looks exactly like the one in my service manual. Probably because it is. If you look at the bottom you'll see it is for B-2 series Dodge trucks. (1950 B-Series Pilot-House trucks)

Between that diagram and what was left of my original harness I was able to make up a replacement harness for my truck

Merle