Farmall Super A Wiring issue.
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=141233
Printed Date: 21 Feb 2025 at 6:25am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: Farmall Super A Wiring issue.
Posted By: HVFDFIREFIGHTER
Subject: Farmall Super A Wiring issue.
Date Posted: 08 Aug 2017 at 5:06pm
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Sorry for the "red" question. I have a 1952 Farmall Super A. I took the Alternator off, replaced the "B", "1" and "2" wires. Used the multimeter red lead to "B" which is also connected to the "2" and black lead to case of the alternator (alternator is removed from the tractor) and checked it by putting drill on it and it does produce a current at the low rpm of the cordless drill. I used the attached wiring diagram. I have replaced all wires on the tractor except for the lights, light switch, and fuse. (Just didn't get that far). I did not put the warning light/diode on either because I didn't have one.
This is a 12 volt, negative ground system. When I go to start tractor, if the two position ignition switch is in, it will not start. If ignition switch is out it will start. This is the correct way it is suppose to operate. My issue is when I go to shut the tractor off. I push the switch in (it should shut off) but nothing happens- tractor keeps running. I take the negative battery cable off, tractor still runs. I take the positive battery cable off, tractor still runs (tractor is running on its own at this point -No battery cables connected at all). The only way I can shut tractor off is to choke it to death. Other than the fact that the warning light/diode and lights are not connected (not drawing the alternator down), I don't see why it is not shutting off. There is a white two terminal porcelin block under the gas tank that has nothing connected to it. Any help would be appreciated.  |
Replies:
Posted By: Walt
Date Posted: 08 Aug 2017 at 6:30pm
| Install the warning light/diode and the engine will shut down when you push the switch in. (Long story behind that sentence.) |
Posted By: DougS
Date Posted: 08 Aug 2017 at 6:32pm
| When you say "diode & light not connected" do you mean there is a solid piece of wire there instead? If so, that is your problem. If not, something is amiss with your wiring. Try taking the 2 wire connector off the alternator after turning the ignition off. I bet the engine will stop. |
Posted By: HVFDFIREFIGHTER
Date Posted: 08 Aug 2017 at 9:16pm
| Yes, I did not hook a light or diode up. Just ran wire straight from alternator to switch. I'm in the process of hooking up a light. Currently light is on when switch is pulled out and I did not try to start tractor. When I push switch in, light goes out. I'm not sure if this little light will draw enough off of alternator. It is 9/16" in diameter to fit in hole in instrument panel. |
Posted By: DougS
Date Posted: 09 Aug 2017 at 5:50am
| The light will. You're seeing classic case of feedback from the alternator to the ignition coil. Either install a light, diode or 47 ohm 2+ watt resistor and your problem will go away. |