Help - Wiring Diagram

[jeff...]

I working on an older style tractor that "had" a old style generator / voltage regulator - now it has a 70's GM Alternator. One problem - once started it won't turn off by the key - I have to choke it to get it to shut off. Guess I got something wired up wrong or need another part??? I was hoping someone could help me figure out what I did wrong. Here's how I got the thing wired. It starts and runs just fine - just won't shut off by the key - it's crazy .



Thanks

[scsmith42]

Jeff, your problem is that your ballast resister is wired incorrectly. Rather than being fed by the alternator, it should be fed by the "run" side of the ignition switch.

The ballast resistor by-pass circuit is in the correct location.

Regards,

Scott

[toolman]

Man I just love this site!! Scott Your the Man!!

[jeff...]

Scott is the man !!!

Scott you mean like this? Looks like I'll need to get another ignition switch... one with a stop, run and start. I can see where the other switch would not break the circuit with juice coming off the alternator to feed the coil - hence the reason it kept running even with the key off...




Thanks

[scsmith42]

Jeff, I'm not sure about where wire number 1 goes to from the alternator, but I do know that you typically have two circuits to the coil. The "start" circuit either comes off of the starter or "start" post on the switch, and provides a full 12 volts to the coil for a hotter spark during starting.

The "run" circuit is fed from the "on" side of the ignition switch and goes through the resistor. It's function is to provide a slightly lower voltage to the coil while the motor is running so that the points don't burn out.

Rather than adding a new key switch, you could wire a starter button in line in-between the battery and the starter solenoid, and move your resistor and alternator circuit over to the "run" side of the key switch.

SS

[jeff...]

Originally Posted by scsmith42

Jeff, I'm not sure about where wire number 1 goes to from the alternator, but I do know that you typically have two circuits to the coil. The "start" circuit either comes off of the starter or "start" post on the switch, and provides a full 12 volts to the coil for a hotter spark during starting.

The "run" circuit is fed from the "on" side of the ignition switch and goes through the resistor. It's function is to provide a slightly lower voltage to the coil while the motor is running so that the points don't burn out.

Rather than adding a new key switch, you could wire a starter button in line in-between the battery and the starter solenoid, and move your resistor and alternator circuit over to the "run" side of the key switch.

SS

Scott thanks - After reading up a little bit on the Delco SI - seems that #1 is a feild wire and is mainly used to light up an idiot light when amperage is low. I really should disconnect that from the Ballast and run it to the idiot light. I'll draw up a new diagram - I already have a 3 post ford ign switch, with the plymouth ballest resistor and Chevy alternator it should fit right in

I hope this one will work - I'll have some fun playing with wires tomorrow.





What you think Scott?

Thanks again man!!!

[Joe Scharle]

Not Scott, but as per your first dwg I can't see how the starter drops out. Last dwg looks good. I only mention this in case your first dwg is incorrect as to how it's actually wired.
Joe

[b4man]

Jeff,
I have a '57 Ford 641 Workhorse tractor that my Dad and I have been refurbishing for the past couple of years. There is a web site called www.Yesterdaystractors.com where I go to get help on anything tractor. I hope this helps in the future.

[Alan in Little Washington]

Jeff- we can put one of my circuit boards in the truck, then fuel it with some high grade rocket fuel, and you'll be good to go!

[jeff...]

Well here is what worked... Ran everything with 10Ga wire except the Battery and starter cables which are 2Ga. I drew it like I ran it instead of a lined diagan for easy reading... In the previous diagram, the light stayed on even with the key off I guess for nothing more than to drain the battery... Anyways thanks everyone for your help, I really appreciate it. If your after an old generator conversion to GM Alternator, with key switch, coil and points ignition this one works. It uses the latest technology, early 70's 63 Amp GM 10SI Alternator, 69 Chrysler Ballast Resistor I think 15 ohms and a early 70's Ford 4 post starter Solenoid - I'm so with the times aren't I? (NOT)

[jeff...]

Couple of things I wanted to point out - just in case anyone wants to use this diagram for conversion.

* I can tell when the battery is not fully charged - the light comes on while the engine is running and the Amp Meter shows only about +2 amps - Once the battery is charged by excess coil voltage, the light goes off and the amp meter shows anywhere from + 10 ~ +50 depending on the motor speed. I thought I may have picked up a bad alternator, so I took it back to where I bought it and it tested fine. I'm still kind of puzzled by this behavior, it's odd... but honestly I think this is because I have a bad battery - I'll have it tested and replace it if it's bad - Think of light that comes from the alternator field (1) wire as the "battery idiot light" that's in your car or truck... It's telling me that my battery is bad

* If the amp meter reads + while starting the motor switch the wires around on the Amp meter - it's wired backwards... No biggie, the amp meter should read -- when cranking the motor.

* What's really cool about this is the two wires that run to the ballast one from the solenoid and one from I (ignition) - you can pull the I wire form the ballast, crank it and it will try to start but once you let the key spring back it dies because the alternator is not supplying voltage to the coil. Unhook the solenoid wire and it cranks all day long but won't start. - pretty cool way to trouble shoot anyways... Scott explained how the wires work before and after the ballast - Thanks Scott... It was easy for me to figure out that everything was working by your explanation...

* Ground the alternator to the negative side of the battery. There's a big lug that's not marked on the backside of the alternator - I used the lug and 10ga wire home run to the negative side of the battery - worked like a champ.

Anyways I learned plenty doing this conversion - I'm going to throw in a volt meter after I pick one up from Nappa. This was a very enjoyable and dirty way to spend the day.

Thanks