8N will not start??

[sherpa]

I have a 1952 8N with a 12 volt conversion.
I have owned the tractor for 9 years with very few problems.
It ran fine when I parked it.
Now it has no spark at the points.
I put in new condenser, new points, new coil.
The switch works fine.
I have about 9 volts at the points, is that all it takes?
I did not do the conversion, I thought it may have something to do with the conversion?
Can someone tell me what to check?
Thanks,
sherpa

 

[dawzie]

OK, I'll try . A pic would help alot also. Is the battery hooked up as negitive ground?? I'll assume it is. With the key "on", take a test light, should have power to (+) side of coil. (-) side of coil should be connected to dist. With points "open", test light should light when touched to (-) side of coil. If it does not light, disconnect the wire going between the dist and coil. Check the coil (-) side again. If it still does not light, bad coil. Re connect the wire, I'm assuming the light lit and doing more testing. Rotate motor to close the points and the light should not light. If it is still lit, bad points/adjustment.

A volt meter can be used also. Check battery voltage first. Then test as stated above. If you are finding more than a one volt drop at the different test spots, try cleaning ALL wire connections including both ends of the big battery wires.

write back

 

[sherpa]

Thanks Dawzie,
I will try this as soon as I can and I will get back to you.
Yes, it is a negitive ground.
sherpa

 

[Soundguy]

9v at the points.. something don't add up..

with an open circuit ( points open ), you should have full bat volts at the feedthru insulator on that sidemount distrib. with points closed.. ya should have NO volts.. as it is GROUND via the points.

9v tells me you have a bad switch.. or bad wire connection.

is this a 12v coil.. or a 6v coil with a resistor ahead of it?

in either case, take a hot wire jumped from the battery and go right to the incoming primary side of the ignition coil then check her out.

points gap at .025 on a sidemount.. plugs gap at .025 as well.

if that gets her.. follow your wireing back fromt he coil to the resistor if any, to the switch, to the wireing terminal, if still used.. etc. somewhere there is a bad connection.. many times it's the switch itself.

( very ocasionally, the feedthru insulator at the distribuitor dies as wel and grounds out the power befor ethe points.. acts as if points always closed.. same as a shorted condensor would do.. same as a shorted phenolic insulation washer under the condensor screw on the breaker plate would do.

there is also a small strip from that feed thru insulator to the points onthe inside of the distrib.. make sure it is not contacting the wall of the distrib..e tc..

soundguy

 

[sherpa]

I have some kind of porcelain terminal I took a picture of, what does it do?
I also have a picture of what looks like a diode on a wire to the 12-volt alternator?
(I took the electrical tape off just for the picture.)
sherpa

 

[sherpa]

soundguy,
You may be right about the switch, one of the last things I checked Friday was the switch and it is losing about 1.5 volts from the Battery side of the switch to the "switch on" side. I just assumed that 10 volts would be enough to run it, am I wrong? It does have a 12 volt coil (brand new). It has always fired right up in the 10 years I have had it other than when it needed points. There is no short on the "new points".

As for the little insulator on the side of the distributor here is a good story for you:
For the first couple of years I had the tractor that wire on the side of the distributor gave me a fit. It was always shorting out or doing something wrong. I removed the wire, insulator and all. I ran a wire straight from the coil through the hole in the distributor to the points. Then filled in the hole in the side of the distributor with silicone, it worked great, no more problems ever with that.

I have company visiting for the weekend and will not been able to work on it until they leave.

Thanks for your help fellows, I will keep you folks informed as soon as I can get back on it.
If you think of anything else I need to check post it on here, I will be checking this forum each day.
sherpa

 

[Cocre]

The picture on the right is a resistor. Take it loose and flip it over any you should see a coil of wire. This is typically used when you are running a 12v battery with 6v distributor electrics (coil and condenser).

 

[Soundguy]

wrong! if the switch is dropping 1.5 volts.. it has SIGNIFICANT resistance.

replace it.

yes the porcelain thing is a ressitor.. and I can't make out the small pic well for the alternator.. but it is common to have an isolation diode in line to the #1 excite terminal on a gm alternator.

soundguy

soundguy,
You may be right about the switch, one of the last things I checked Friday was the switch and it is losing about 1.5 volts from the Battery side of the switch to the "switch on" side. I just assumed that 10 volts would be enough to run it, am I wrong? It does have a 12 volt coil (brand new). It has always fired right up in the 10 years I have had it other than when it needed points. There is no short on the "new points".

As for the little insulator on the side of the distributor here is a good story for you:
For the first couple of years I had the tractor that wire on the side of the distributor gave me a fit. It was always shorting out or doing something wrong. I removed the wire, insulator and all. I ran a wire straight from the coil through the hole in the distributor to the points. Then filled in the hole in the side of the distributor with silicone, it worked great, no more problems ever with that.

I have company visiting for the weekend and will not been able to work on it until they leave.

Thanks for your help fellows, I will keep you folks informed as soon as I can get back on it.
If you think of anything else I need to check post it on here, I will be checking this forum each day.
sherpa

 

[sherpa]

Soundguy wrote:
take a hot wire jumped from the battery and go right to the incoming primary side of the ignition coil then check her out

OK, that fired it up, runs perfect!!

I checked the reisister and its burn into.
Did I burn it up with the hot wire or is there a short somewhere or was that the problem?
What are my options for replacing the risister, do I get another one just like this one or is there something better to replace it with?
Where is a place to get a new resister?
Should I run all new wire?

Man, it was fun to hear that old 8N fire up and run!!
sherpa

 

[Soundguy]

replace the resistor.. it is 'open'. no.. a short didn't likely kill it.. nor your hot wire.. in fact.. you hot waire was an artificial short circuit taking the resistor side of the circuit out of circuit so to speak.. IE.. a bypass.. since the origin of that circuit is the bat hot anyway.. there is NO WAY for a backflow of current if it's wired correctly.

just replace it and then check it out again.. I still suspect the ignition switch.

try this.. jump from one side o fthe ressitor tot he other.. will she start? yes.. then just repalce the resistor..

no, then jump from in front of switch ( power side ) to past broken resistor... she start? yes.. then repalce switch and resistor.

no.. then keep following the wires back till you find the bad connection betweenthe battery and start switch..

Now here's some even better advice.

ditch the resistor an old 6v coil and hit a napa and ask for a IC14SB it's about a 16$ REAL NATIVE 12v coil.. needs no resistor.. has NO internal ressitor.. it's primary is simply sufficient gauge and # of turns to be 3+ ohms.

get that coil, and the new switch if needed and you should be set.

new coil costs perhaps 8-10$ more than the resistor.. but is a better deal.. old coil is not oil potted.. new coil is.. that's way better thermal disipation properties.

soundguy