8N - Wiring Questions (Previous Owner Hack Job)

[tcweb]

Good morning,

I have an 8N. Let me list what I have:

12v conversion done with a coil that is separate from the distributor. (not sure if that is typical?)
Coil looks to be similar to what I'd see on an old Mustang.

Resisitor behind dash - not used
Original push start near shifter - not used
Dashboard Amp meter - reads continuity between the two posts.

Single wire alternator

distributor (front mount) has 2 wires going in the top where (I believe) the original coil was mounted.

Start switch - aftermarket 4 position (ACC, OFF, IGN, ST)

Here's my first observations:

Nothing is physically connected to the ACC wire of switch. Yet when I turn the switch to the left (ACC), the starter kicks in! I can't explain that...
When switch is off, I seem to be registering 12v across both sides of the coil! so off is not really off?

Then when I turn switch to "on", no starter engagement. spring return start: no starter.

So I disconnected the ignition switch entirely and tested it ont he bench. Seems that "IGN" and "ST" are both getting power. (continuity with BAT) all the time.
So I think the switch is defective. I have a new one coming today. Still a cheap import, but I could get it quickly.

Now...all of that said...how do I go about getting things back together?

I think the combination of the broken/defective ignition switch may have caused the previous owner to re-wire things.

Where would I start? With the newer style 12v coil, do I need the inline resistor?

I have looked a dozens of forum posts, but most are dealing with original 6v or a different 12v conversion than what I have (newer style coil).

-Tom

 

[HarryVanderpool]

Hack job is right!
The first order of business is to decide that you ARE NOT going to attempt to "get it running" in it's cobbled and unsafe design.
Start from scratch.

 

[MeanGene1]

Sounds like boogered together with some original and some different parts. When I did mine (and my 850) I got the kits from the site, which gives you the 1-wire alternator that excites at low rpm, with the correct pulley. Mine is side-distributor so a little different, but the bracket is very nice and belt fits good. I didn't use the included wire harness as I had a big spool of 10ga. I also went with the automotive type solenoid, which looks similar but operates differently from the tractor type. The push button setup was blooey on the 8N, so I went with generic key switches so both are key-start now (que screaming from the purists). This gives me a complete, very simple auto/truck type 12V system, with a Mopar ballast resister and the 12V jumper wire from the auto solenoid to the coil for starting, and allows me to keep one spare solenoid and resister for most of my junk. Turn on the gas, wait about 30 seconds and turn the key, and it will turn over about half way and it's running. And I kept all the original 6V stuff from both in case any future owners want to switch them back to row-row-row

 

[tcweb]

Hack job is right!
The first order of business is to decide that you ARE NOT going to attempt to "get it running" in it's cobbled and unsafe design.
Start from scratch.

That is the plan, but I'm hoping to not have to start completely from scratch. I have seen other 8Ns that use the automotive style coil and relay, so I know it's doable.

I guess I'm looking for someone to share the basic wiring, so I can see what is advisable. (since stock 6v is not on my radar....)

 

[tcweb]

Sounds like boogered together with some original and some different parts. When I did mine (and my 850) I got the kits from the site, which gives you the 1-wire alternator that excites at low rpm, with the correct pulley. Mine is side-distributor so a little different, but the bracket is very nice and belt fits good. I didn't use the included wire harness as I had a big spool of 10ga. I also went with the automotive type solenoid, which looks similar but operates differently from the tractor type. The push button setup was blooey on the 8N, so I went with generic key switches so both are key-start now (que screaming from the purists). This gives me a complete, very simple auto/truck type 12V system, with a Mopar ballast resister and the 12V jumper wire from the auto solenoid to the coil for starting, and allows me to keep one spare solenoid and resister for most of my junk. Turn on the gas, wait about 30 seconds and turn the key, and it will turn over about half way and it's running. And I kept all the original 6V stuff from both in case any future owners want to switch them back to row-row-row

Sounds like you have done something similar to what was done to this 8N, only CORRECTLY.

As soon as I saw 12v on either side of my coil when the key was OFF, I pulled the battery ground, and said NOPE. Time to research and troubleshoot.

I'm sure that someone started randomly swapping wires to find a configuration where the tractor would turn over...and then gave up when it wouldn't fire.

My biggest question is about the resistor. Was it only needed for the 6v coil? Or is a resistor needed even with the newer automotive style coils?

Also you mentioned buying kits from "the site". Which site are you referring to? The one run by the Gingells?

-Tom

 

[Jim.ME]

Sounds like you have done something similar to what was done to this 8N, only CORRECTLY.

As soon as I saw 12v on either side of my coil when the key was OFF, I pulled the battery ground, and said NOPE. Time to research and troubleshoot.

I'm sure that someone started randomly swapping wires to find a configuration where the tractor would turn over...and then gave up when it wouldn't fire.

My biggest question is about the resistor. Was it only needed for the 6v coil? Or is a resistor needed even with the newer automotive style coils?

Also you mentioned buying kits from "the site". Which site are you referring to? The one run by the Gingells?

-Tom

This site, Yesterday's Tractors, sells parts to support this forum. PartsASAP is the parent company of YT, they sell parts and operates several salvage yards.

 

[MeanGene1]

The site means this site- their 12V conversion kits are quite nice, and the kits including the brackets, wiring, belt etc are only a little more than just the alternator. And the alternators excite at quite low RPM as advertised

 

[soaked]

Hi tcweb, welcome aboard!
Pertronix makes kits to mount round can coils externally, along with electronic ignition kits.
Here is their 1247xt, available here

Got points or pertronix?
Suggest take a look.
If pertronix, must also have suppression spark plug wires, no copper core.
This kit comes with a 3.0 ohm coil. (measured across the pos and neg small terminals).

 

[tcweb]

Hi tcweb, welcome aboard!
Pertronix makes kits to mount round can coils externally, along with electronic ignition kits.
Here is their 1247xt, available here View attachment 167531
Got points or pertronix?
Suggest take a look.
If pertronix, must also have suppression spark plug wires, no copper core.
This kit comes with a 3.0 ohm coil. (measured across the pos and neg small terminals).

OK, I haven't been brave enough to pull the distributor cap, for fear of something falling out. I'll check it out. I have a pertronix on my old mustang, so I'm fairly familiar. And maybe that explains the second wire going into my 8n distributor.

I'll check, and post some pics.

 

[Jimps]

Sounds like you have done something similar to what was done to this 8N, only CORRECTLY.

As soon as I saw 12v on either side of my coil when the key was OFF, I pulled the battery ground, and said NOPE. Time to research and troubleshoot.

I'm sure that someone started randomly swapping wires to find a configuration where the tractor would turn over...and then gave up when it wouldn't fire.

My biggest question is about the resistor. Was it only needed for the 6v coil? Or is a resistor needed even with the newer automotive style coils?

Also you mentioned buying kits from "the site". Which site are you referring to? The one run by the Gingells?

-Tom

Welcome Tom!

I have a similar setup with a front mount distributor using a round can 3ohm coil. Previous to me someone had hogged out the guts of the square coil on top of the distributor and ran a wire down to the spring at the bottom of the square coil. It is 12 volts, negative ground now. I bought that Pertronix conversion kit but mine works fine the way it is. I may change it out one day.

Your question about a resistor: Check your round can coil. If it is a 3ohm coil (mine is) then no external resistor is required. You will also NOT need the infamous ballast resistor for that setup. 1.5ohm coil will require an appropriate resistor to get as close to 4 amps as possible. Using Ohm's law, 12 volts (your setup) divided by the ohms on your round can coil will tell you the amps. 12/3=4amps, no resistor needed. 12/1.5=8amps - too much! Someone please correct me if I am wrong, but a 1.5ohm resistor would be required for the 1.5ohm coil.

However, if I were in your situation with questionable wiring I would strongly consider either getting a proper 12volt compatible square coil (ballast resistor required) and wire it like original (Google wiring diagrams by jmor) OR get that Pertronix kit and move on.

Lots of help here.

We look forward to your progress and eventual resolution.

Hope this helps.

Jimps in GA.