59 Apache ignition wiring help needed

[Steel_valley]

So, I got a new key switch from Brothers, I also bought the harness they require for a 59 to use this switch. I messed with it for several hours and couldn't get the power to shut off to the coil. After a while I decided to remove the adapter harness that brothers sells and hooked it up direct as it was from the factory. The truck now runs, starts and stops on its own like it should.

BUT, when the truck is running, with the points ignition, I'm reading 15-18v on the positive side of the ignition coil. I tested the ballast resistor and it's reading 1.8-2 ohms resistance. To test the coil when running, I touch the positive test lead to the coil and negative lead to the battery. The negative side of the coil is feeding the dizzy. The positive side is coming from either the key switch or the ballast resistor, I'm having a hard time tracing that wire. What can I do to get this voltage down? Or is there something else I should test? My brain hurts from working on this lol. Any assistance is appreciated.

Oh and the ballast resistor has 3 wires on it, I'm colorblind, but I think 2 green and one brown. Is that right? I removed the one that comes directly from the ignition switch to the resistor and the truck still runs. I have 12v key switch hot going into the one end of the ballast resistor.

[dmjlambert]

I suggest start with measuring the voltage at the battery posts, when the truck is off and when you have it running. What is the voltage?

Do you know what type of alternator and regulator setup you have?

[Steel_valley]

I have a 10si, it's currently disconnected due to wiring corrections. Voltage at the battery posts I didn't measure.

Could the alternator being disconnected be affecting it?

[dmjlambert]

I don't think alternator disconnected could cause this condition you describe. I would be interested in hearing about the voltage at the battery both with truck running and with it not running. That's starting with the basics. Are both the plastic plug and the positive post on the alternator disconnected?

[Steel_valley]

The cable from the alternator to the battery was not, and I think I have the alternator T1 cable hooked up wrong, but it's currently disconnected now.

[dmjlambert]

I'm not following what you say. I don't know what a T1 cable is. Is every wire disconnected from the alternator, including the post connector and the plug?

What is the voltage reading on the battery with the engine not running, and with the truck running?

[Steel_valley]

T1 cable from the alternator, it has a 10si alternator on it.

Now, the battery is 13.5 volts, roughly when shut off, running it is 17-19 volts. The alternator is still disconnected, could that be why?

[dmjlambert]

I'm afraid this is above my knowledge level. I don't know how there could be a difference in voltage produced by the battery when the alternator is disconnected. With the engine running or not running, I think the voltages should be the same. Either you have a different definition of alternator disconnected than I do, or voltage is being generated from some device on the truck other than the alternator. Perhaps it is the coil.

I hope somebody else more knowledgeable than me will see this thread and give their opinions or suggestions on what more to investigate.

I thought I knew about 10SI alternators, but I have not heard of a T1 cable. I know of the cable that goes to the main output post of the alternator, and a cable with 2 wires that plugs into the alternator with a plastic plug (those 2 terminals are warning lamp/exciter voltage, and voltage sense), and the ground wire that goes to the alternator case.

[Steel_valley]

Originally Posted by dmjlambert

I'm afraid this is above my knowledge level. I don't know how there could be a difference in voltage produced by the battery when the alternator is disconnected. With the engine running or not running, I think the voltages should be the same. Either you have a different definition of alternator disconnected than I do, or voltage is being generated from some device on the truck other than the alternator. Perhaps it is the coil.

I hope somebody else more knowledgeable than me will see this thread and give their opinions or suggestions on what more to investigate.

I thought I knew about 10SI alternators, but I have not heard of a T1 cable. I know of the cable that goes to the main output post of the alternator, and a cable with 2 wires that plugs into the alternator with a plastic plug (those 2 terminals are warning lamp/exciter voltage, and voltage sense), and the ground wire that goes to the alternator case.

I'm not really sure how to respond to this, different definition?? Ok, to put it lightly, the alternator is hanging on the engine, with a belt around it and no wires connected to it, perhaps I got a telepathic alternator right? What other type of definition is there?


And here is an extremely basic diagram of a 10SI alternator, it even had the T1 and T2 connections labeled in the drawing.

[dmjlambert]

With the alternator wires disconnected, I don't know how you're getting 17-19 volts from your battery with engine running. I do think that needs to be corrected. Your points won't like it, and other devices you may have such as lights and radio, etc. won't like it. How about that voltage meter you're reading with, could it be defective?

[Madkidd007]

To elaborate on the definition of disconnected, do you only have the “T1” connection disconnected or is the battery wire disconnected also? Thinking that the alternator is self exciting and charging with no signal wire. But this would only be the case if the battery wire is still connected.