Ford 8N electrical issues after attempted jump start 6v-12v

mtnscott

New User
I'm helping a friend diagnose and repair a problem with his 1943 8N Ford tractor. I had it running great last season, but unfortunately he used his tractor to attempt a jump start with his SUV. He connected the SUV 12V system to the tractor's 6V system. The tractor was running, but when the SUV started, the tractor died immediately. I have checked the battery, the ignition switch, the starter button, the starter, the resistor and all wiring up to the voltage regulator. All appears to function properly. There is no spark to any of the spark plugs with turning the engine over with the starter. My initial thought was a blown coil or bad voltage regulator, but I prefer to not get into a parts replacement mode of repair. Does anyone have a thought about the likely component that failed. The tractor is in a remote location so I'd prefer to buy the parts necessary and do the repair at one time. Thanks for any help that you can provide.
 
#1 no such thing as a 1943 8N the first one did not come out till 1948 ya some where made in 1947 but still call a 1948 just like with cars now day you can buy a 2018 car in 2017
#2 front mount distributor or side mount makes a difference as to what maybe wrong.
#3 jumping a 6 volt battery direct to a 12 volt battery is a good way to cause the 6 volt battery to explode and if it does good way to go blind had that happen to a friend years ago.

I would start by checking the points and make sure he did not cause them to burn which would cause the problem it now has with no spark
 
Yep, the 8N Model was first produced in July, 1947 as the new 1948 Ford Tractor model, 8 designating model year, N designating tractor. Does yours have a 3-speed or 4-speed tranny? 9N/2N models had 3-speeds, the 8N had the 4-speed. If tractor has a 6 volt battery and you tried to jump it directly from a 12 volt battery, man you like to live dangerously. there is a certain method to safely jump starting a 6 volt set up -see Bruce(VA)'s 75 Tips LINK below. You say you checked everything and they are all working yet you have no spark. You don't mention distributor so points would be the first thing to look at. Getting fuel is next...

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<font color="#FFFFFF" size="3">*9N653I* & *8NI55I3*</font>​
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75 Tips for N Owners
 
(quoted from post at 07:36:04 06/01/17) I'm helping a friend diagnose and repair a problem with his 1943 8N Ford tractor. I had it running great last season, but unfortunately he used his tractor to attempt a jump start with his SUV. He connected the SUV 12V system to the tractor's 6V system. The tractor was running, but when the SUV started, the tractor died immediately. I have checked the battery, the ignition switch, the starter button, the starter, the resistor and all wiring up to the voltage regulator. All appears to function properly. There is no spark to any of the spark plugs with turning the engine over with the starter. My initial thought was a blown coil or bad voltage regulator, but I prefer to not get into a parts replacement mode of repair. Does anyone have a thought about the likely component that failed. The tractor is in a remote location so I'd prefer to buy the parts necessary and do the repair at one time. Thanks for any help that you can provide.

I'll add some clarification. The tractor is a 1943 2N, but the previous owner had replaced the 2N engine with an 8N engine. It is 3 speed with the distributor located near the front of the engine on the right side. I didn't check the points to see if they were stuck or badly pitted. The fuel system is working properly, but the plugs aren't firing.
 
(quoted from post at 09:49:33 06/01/17) #1 no such thing as a 1943 8N the first one did not come out till 1948 ya some where made in 1947 but still call a 1948 just like with cars now day you can buy a 2018 car in 2017
#2 front mount distributor or side mount makes a difference as to what maybe wrong.
#3 jumping a 6 volt battery direct to a 12 volt battery is a good way to cause the 6 volt battery to explode and if it does good way to go blind had that happen to a friend years ago.

I would start by checking the points and make sure he did not cause them to burn which would cause the problem it now has with no spark

Thanks for your advice and the reply. I added clarification on the tractor year and model. I'll check the points. I also gave the tractor owner a refresher course in Jump Starting 101.
 
Is the distributor cap a 4 nipple cap or a 5 nipple cap?? The 4 nipple one is what is called a front mount and the points are set to 0.015 but if it has a 5 nipple cap then the points need to be set at 0.025.
 
Well, you can jump a 6v system with A 12 V system, if you simply ground the 12 V system on your six volt tractor frame and then touch the positive cable to the positive cable of the starter,that will cause the starter to engage and if you have enough charge in the six volt battery and the coil and points are good, it should start. I think what happened here was that someone connected the 12 V battery to the 6 V battery in order to jump it. That could have caused a meltdown in the coil and battery. If you have to buy new coil and if the battery is toast, then I would certainly consider converting to a single wire 12 V system with 12 V alternator. The points should be changed and will easily accept the 12 V system. Coil should be changed to 12 coil, which will allow you to use the ballast reducer of the original six volt system. The starter can easily handle the 12 V system without modification. This website can give you more information on converting to a 12 V system and can direct you to parts distributors that will give you the parts necessary to make the conversion.
 
Tell him not me. I know what can/will happen if you hook a 12 volt battery to a 6 volt battery you can cause the 6 volt battery to explode and that can cost you your eyes i know I had a friend who now cannot see because of that
 
"you can jump a 6v system with A 12 V system, if you simply ground the 12 V system on your six volt tractor frame and then touch the positive cable to the positive cable of the starter,"

You have the right concept in that when jumping 12 volt to 6 volt, make your hot connection direct to the starter, not to the battery. If your 12 volt vehicle and 6 volt tractor are both configured negative ground your description will work.

However, if jumping with a 12 volt vehicle I would assume it to be negative ground. If a 6 volt tractor I would assume it to be positive ground, thus the positive battery post on the tractor goes to frame ground, not the starter.

If a tractor is involved in the procedure I would first want to confirm whether it is positive or negative ground.

Let?s assume the 6 volt tractor is positive ground. When I read "ground the 12 V system on your six volt tractor frame" I assume you are connecting the negative side of 12 volt battery which connects to vehicle frame to the 6 volt tractor frame which is connected back to the positive battery post. If you then were to in any way connect 12 volt positive side of the vehicle to the 6 volt positive battery post you are direct shorting your 12 volt battery and will make sparks and smoke

When using a battery charger or jumper cables you can do yourself a big favor and prevent potential disaster by throwing out the term "ground". Instead think in terms of positive and negative.
Do not let the vehicle and tractor frames come in contact in any way. Then simply connect positive of one to positive of the other , and negative of one to negative of the other. Remember that on a positive ground tractor the frame is positive and the hot side is negative. This way ?that positive ground thing? won?t become a confusing issue.
 
(quoted from post at 14:28:48 06/02/17) Is the distributor cap a 4 nipple cap or a 5 nipple cap?? The 4 nipple one is what is called a front mount and the points are set to 0.015 but if it has a 5 nipple cap then the points need to be set at 0.025.

The tractor engine is a "4 nipple" distributor with the cap located on the front of the engine. Two plug wires come out the right side and two wires come out the left side. I'll replace the points and gap to the proper dimension.
 

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