# 1941 Case Ignition Wiring Problem



## Larry A. Lamp (Nov 23, 2004)

Depending on what type of starter switch you have chosen, here is what you must do. If you are using the original large push starter switch, attach the wire that feeds the amp meter to the post on the starter switch that goes to the battery. Only the heavy wire to the starter should be on the other starter switch terminal. This gives a constant live source of power to the amp meter. Attach the wire for the ignition switch to the negative side of the amp meter. The other terminal of the ignition switch connects to the balast resistor.
If you are using a solenoid, the battery cable and the amp meter plus side are connected to the same large terminal. Again only the starter cable is connected to the other large terminal. The negative amp meter terminal goes to the ignition switch. If you are using a turn key ignition switch the terminals on the switch will tell you where each wire goes. A small push button starter switch will require a wire from the negative amp meter to the switch and from the other terminal on the switch a wire goes to the solenoid energizing terminal. 
After being wired this way, you may find another problem. The small wire that supplies power to the alternator may need a diode between the ignition switch and the alternator to prevent feed back from the alternator from preventing you from stopping the engine when the ignition switch is turned off. You may not have this problem if your alternator was sold for your intended application. Salvage yard alternators require a diode. 
This works for me, I hope it works for you too!


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## Rodster (Sep 26, 2003)

that sounds like the answer to one of CHRPMASTERs probelms. 
His 12 volt conversion would not shut off with the key. Last I heard he is having trouble with his starter.
Rodster


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## caseman-d (Nov 29, 2003)

Larry,
Thanks for the information and welcome to the case forum. Electrical problems always seem fustrating to me. hope you keep comming back.
caseman-d


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## jodyand (Sep 16, 2003)

Welcome Larry:friends: good info something to keep around.:thumbsup:


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## balmoralboy (May 22, 2004)

Welcome, Larry Lamp. You have shed light on what is a perplexing problem for us wrench guys. You have lived up to your name!

With clear, to the point explanations like that, you're a keeper! Please keep the posts coming.


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## chrpmaster (May 5, 2004)

Welcome Larry

With answers like that you are my new best friend. :worthy: :worthy: 

You clarified my issue very well - in fact I think I even understood it! 

Yes Rodster I am still having starter problems but found a local guy who will fix it. somehow had a problem with the cable attached to the post on the side of the starter. Someone tried to tighten it and goofed it up though I will not mention any names
 :lying: 

As soon as I get it back I will be able to check if I followed your instructions correctly. 

By the way you mentioned that I may need a diode. First what is a diode and second where do I get one and third are there different sizes if so what size do I need?

Thanks
Andy


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## bontai Joe (Sep 16, 2003)

Very glad to have someone that can explain electrical stuff in everyday language! Welcome to the forum!


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## Larry A. Lamp (Nov 23, 2004)

*To Andy--Diodes*

Diodes come in all kinds of shapes and sizes. What they are is a one way switch. Current will only flow in one direction. Unless they are marked you will have to test them to find out which way that is. The ones I have I got at Napa. They came three in a box. They are used in alternators. They are about 1/2" in dia. with a bare solid wire sticking out the back about 1 1/2" long. I run my wire from the ignition switch to the balast resister. From that point, I install the diode, current flowing out, to the small alternator wire on the wide thin plug on the alternator. The plug is referred to as a pip tail. When the ignition is turned off the alternator will not backfeed current to the distributor.
To get all the wiring loose ends together, I use a 10ga. wire to the + amp gague terminal. the other big wire on the pig tail is attached to the bat. post marked on the alternator along with the 10ga. wire to the amp meter. I use salvage yard alternators made by delco since I am familiar with them. Also to make this the least expensive to do a 12v conversion, use only alternators with internal regulators. They are late 70's to 80's vintage and GM made a lot of them.
I mentioned the diode was 1/2" in dia. You will need to wrap bare wire around the round part tightly and wrap the whole thing in plastic tape leaving enough wire to make the neccessary connections. 
I tried to use some small diodes from Radio Shack but they couldn't handle the load. I have used the Napa ones for four years without any problem. 
I would tell you to solder the wire wraped around the round part, but too much heat will damage the diode. You might get away with it, so you can experiment if you wish!
For the record, I'm a Case collector. I have 4 DC's and 5 SC's. One DC restored and 3 SC's restored.


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## chrpmaster (May 5, 2004)

Larry

as my 11 year old likes to say "you da bomb". (I think thats a good thing.  )

Anyway welcome to the forum and I'm sure I (and many others) will make use of your expertise on these and other case matters.

Andy


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