9N ignition system

[tToubles]

Can any one help me?
I have taken a working distributor assembly and 6 volt coil off my brothers 9N tractor and placed it on mine. I can not get any spark out of the distributor cap or to the plugs. Does any one have any explanation of why I can get fire at the coil but not to the plug wires. Once again if I remove all these parts from my 9N and put them on my brothers 9N they work fine and his tractor runs. I have my tractor wired like this. I have the coil wire going to one side of the key switch. The other side of the switch goes to the positive side of the celanoid. There is no cut out switch being used in this set up.

 

[Brian Bell]

Have you tired jumping around the notorious "weak-sister" ignition switch?

 

[HCooke]

When you say 'distributor assembly' I assume you are including the coil and the cap??? What is the condition of your spark plug wires?? Are they resistor wires or solid copper??? Answer back.

 

[souNdguy]

one thing.. with your description of essentially, battery to key to coil.. you will very soon burn yer coil and points out.

2, if you can read voltage at the coil primary wire but get no spark.. and swapping a good distrib does the same.. and yours works ont he other machine.. then i suspect your wireing to/from the key switch is bad.. or the switch itself is bad .. voltmeters have no real load and can read voltage thru a bad connection.. however when the points close and want 5-6 amps of current ( since you have no resistor! ).. then the bad connection likely lets little or no current flow.

verify with a gator clip jumper wire from bat to coil top ( hotwire )

soundguy

 

[dennisinoklahoma]

Always check for the simple mistakes....

If you have a hot spark from the coil wire going to the distributor and no spark from the distributor to the plugs, then you may have left out the rotor which carries the spark from the center of the distributor to the individual plug wires. Yes, I have been guilty of doing this myself.

Also, you could be grounding out the spark inside the coil.

Also, if you have the front mounted coil and distributor, the spring may need to be stretched to ensure it makes contact between the coil and cap / rotor.

Also, the front mounted distributors have a very thin strip of insulation on the internal mounting screw for the points, if you tighten the screw too much or if you tighten the timing screw on the outside of the distributor too tight, the excessive tightening can cause a short across the insulation.

You can make your own insulator at the screw using a tiny plastic washer.

Good luck. email me if you need more help, I have a lot of bad experience with the front end distributors and pretty much can help you with the ignition problem.

You may want to consider trading out one item at a time for troubleshooting, a crack in a rotor or cap can short out the coil spark.
[email protected]

 

[dennisinoklahoma]

I just reread your initial post. You stated you are coming off the "positive" side of the solenoid, your solenoid power should be coming from the negative battery terminal, not the positive.

The original 6 volt system is a positive ground system where the negative side of the battery goes through the ammeter then to the switch then to a resistor then to the coil.

The resistor simply drops the voltage by about 25%. Bypassing the resistor will shorten the life of the points and maybe the coil.

 

[dennisinoklahoma]

Darn, I forgot to recommend the first three steps in ignition troubleshooting for the Ford.

1. Verify your battery is charged.

2. Verify the positive ground strap is clean and tightly connected at the battery and on the engine. A rusty connection at the engine will allow you to measure voltage but will not provide proper current.

2. Disconnect the coil wire. Hook a wire directly to the negative battery post and hook the other end directly to the coil. This will bypass all internal wiring shorts and hookup errors.

good luck

 

[tToubles]

My tractor has a Negative groung set up. I have power already at the coil. I just dont have it at the distributor. I am using a new fully chatged 6 Volt battery. I checked it with an Amp. meter. Once again if I remove all my components and place them on my brothers tractor. His tractor runs. I replaced my Positive cable because it wasn't making a good connection. Thanks for your help! All assistance is appreciated. This is driving me crazy. Would I get power at the coil by connecting a cable from the negative post to the coil if my tractor is a negative ground set up?

 

[dennisinoklahoma]

Why did you go to a negative ground? Just curious.

I am not sure but it seems the dc starter motor should turn backwards with a negative ground. Does your starter turn in the proper direction?

Also, if there is a diode in the ignition curcuit, it acts like a check valve and power will pass in only one direction. The capacitor in the distributor may be acting as a diode. If you have a positive ground capacitor, that will be your problem as it is not charging up properly.

Anyway, try two things. First, try the easy, change to a positive ground and see if things work.

If not, check the ground at the coil.

The hot wire to the coil has to go to ground through the points system via the distributor so the distributor has to be well grounded which is not usually a problem. For the top mounted coil, the ground has to occur through the distributor to the block via the bolts because the distributor usually has a gasket between the engine and the distributor.

Note: Do not hook an ohmmeter to a power source, it may burn out the ohmmeter.

To check the system for continuity, disconnect the coil wire and put tape over it to keep it from shorting to the engine block.

To test a negative ground system. Hook an ohm meter to the coil, red to the coil, black to the ground post on the battery. Rotate the engine and watch the ohmmeter, each time the points close, the ohmmeter should show continuity.

To test a positive ground system, switch the probes. If it works one way and not the other, it indicates a built in diode in the coil or indicates the capacitor is the wrong type.

If it works both ways, then the grounding type does not matter.

If it works neither way, you most likely have an open in the cicuit, usually between the coil and distrbutor (stretch the spring).

If it has a continous continuity, you have a short, usually before the circuit gets to the points.

Good luck

 

[JMOR]

(quoted from post at 05:12:18 10/22/09) Why did you go to a negative ground? Just curious.

I am not sure but it seems the dc starter motor should turn backwards with a negative ground. Does your starter turn in the proper direction?

Also, if there is a diode in the ignition curcuit, it acts like a check valve and power will pass in only one direction. The capacitor in the distributor may be acting as a diode. If you have a positive ground capacitor, that will be your problem as it is not charging up properly.

Anyway, try two things. First, try the easy, change to a positive ground and see if things work.

If not, check the ground at the coil.

The hot wire to the coil has to go to ground through the points system via the distributor so the distributor has to be well grounded which is not usually a problem. For the top mounted coil, the ground has to occur through the distributor to the block via the bolts because the distributor usually has a gasket between the engine and the distributor.

Note: Do not hook an ohmmeter to a power source, it may burn out the ohmmeter.

To check the system for continuity, disconnect the coil wire and put tape over it to keep it from shorting to the engine block.

To test a negative ground system. Hook an ohm meter to the coil, red to the coil, black to the ground post on the battery. Rotate the engine and watch the ohmmeter, each time the points close, the ohmmeter should show continuity.

To test a positive ground system, switch the probes. If it works one way and not the other, it indicates a built in diode in the coil or indicates the capacitor is the wrong type.

If it works both ways, then the grounding type does not matter.

If it works neither way, you most likely have an open in the cicuit, usually between the coil and distrbutor (stretch the spring).

If it has a continous continuity, you have a short, usually before the circuit gets to the points.

Good luck

Attention tTroubles:
DennisOK' s post has so many things wrong in it's content, that it isn't worth the time to point out all of them. You need to ignore it, lest you do damage or totally confuse your self. This is not an attack on Dennis, just fact & an attempt to help tTrouble. Wrong "info" can be worse than none at all. I'm sure Dennis was just trying to help, but.........