Cushman OMC Resistor Voltage

[KevinRB]

I am getting 12 volts on both sides of my resistor on 22 hp omc. I believe I am supposed to get 12 on input and about 7 on output. Does this mean the resistor is bad or could it be another problem?
Thanks

[CharleyL]

How are you measuring the resistor? Where are you connecting the other lead? The resistor is in series with the two coils, which are also in series. The points connect the resistor and coil circuit to ground when the points are closed. If the points are open you will likely get the same voltage on both ends of the resistor when checking from either end of the resistor to ground. I think your resistor is good and you have open points, or an open circuit somewhere else. If the points are open, no current is flowing and you should get 12 volts on both sides of the resistor when measured to ground.

Do you have a multi-meter that can read ohms? If so, with the ignition switch off, and the meter set to RX1 ohms scale, connect one lead to one end of the resistor and the other lead to the other end of the resistor. If you get a reading that is anywhere between 15 and 45 ohms, the resistor is good. These resistors usually get broken, since they have a porcelain body that breaks easily, long before their electrical properties go bad.

Maybe you should describe the problem that you are having so I can help you diagnose it.

Charley

[KevinRB]

Charley, Thanks
I was checking with multi meter set on volts dc with the black lead ground to motor and red lead to the resistor. I will recheck today making sure the points are closed and also check the ohms reading.
I have the motor in the cart and wired per diagram but the key switch will not turn the motor over. I can however jump the solenoid and turn it over but with no spark.
Ill let you know what I find later today.
Thanks Again. I appreciate your help.

[CharleyL]

What is the model number of your cart? Are you using the correct schematic for it. With the model number I could try to find the schematic and then step you through the diagnostics.

Your voltmeter readings indicate to me that your ignition switch is on and voltage is reaching, and going through the resistor. It should then go to a terminal on one of the coils, then the other terminal of that coil should jumper to a terminal on the second coil, the second terminal on the second coil should be wired to the points.

With the points open and the key switch on you should be able to see a voltage at each one of these points using the red lead to test and with the black lead of the voltmeter connected to the motor or chassis and all of the readings should be 12 volts, or close to it. With the points closed and the key switch on you should see a voltage at each point, but the voltage reading will be less and less as you move toward the points. The points lead should show zero volts, or close to it.

Charley

[KevinRB]

Charley
Its a 735 golfster. I have the wires hooked up like it says in my book. In the process of checking as you said I have now discovered the ignition switch works when points are closed but not when open. Also when trying to start with the key and points closed engine does not spin but agitates. I hope that info helps find the problem.
Kevin

[CharleyL]

I don't understand your post at all. Try again.

Charley

[KevinRB]

Charlie, Sorry about the confusion.
Here is what I have...... + from battery to right side of solenoid with connecting wire to ignition switch terminal marked battery. Wire on next terminal of solenoid going to ignition switch marked acc. Next wire on solenoid goes to resistor with a joining wire going to + side of coil. Wire on other side of resistor goes to ignition switch marked solenoid. The wire from - side of coil goes to timer. Coils connected together + to -. And the left side of solenoid connects to starter motor.
Now the only time it turns over with the key is if the poi ts are closed. If they are open I get nothing.
I hope this is not more confusing.
Thanks
Kevin

[CharleyL]

"Here is what I have...... + from battery to right side of solenoid with connecting wire to ignition switch terminal marked battery. Wire on next terminal of solenoid going to ignition switch marked acc. Next wire on solenoid goes to resistor with a joining wire going to + side of coil. Wire on other side of resistor goes to ignition switch marked solenoid. The wire from - side of coil goes to timer. Coils connected together + to -. And the left side of solenoid connects to starter motor.
Now the only time it turns over with the key is if the poi ts are closed. If they are open I get nothing.
I hope this is not more confusing."


Kevin,

I think the highlighted wire above should not be going between the solenoid and the coil it should be going between the ignition switch and the first spark coil. I can't see the solenoid to know which design that it is but there should be 2 big terminals and two small terminals. One of the big terminals should be connected to + on the battery. The other big terminal should connect to the starter. The remaining 2 terminals on the solenoid are the connections to the internal coil (the solenoid coil inside it) One of these needs to connect to the ignition switch connection marked start. The other small terminal of the solenoid needs to connect to the motor or frame.

I haven't found a schematic for your cart, so I'm a bit blind here. Could you scan a copy of your schematic and post it? A single page per file should make it big enough for me to be able to read it. Use 150 dpi if you can.

[KevinRB]

Charley
I moved the wires as you said and I can now turn the engine over with the key. However I now have a wire from the single side of the resistor with no where to go. The small terminal on the solenoid where it was now goes to the frame as you said. I'm sure I am missing something obvious just cant nail it.
I do appreciate the help.
Kevin

[CharleyL]

Kevin,

One end of the the resistor should be connected to the key switch, the terminal on the switch that has voltage between it and the motor case or frame when you check with the volt meter. The other end of the resistor should connect to the small positive terminal on the first coil. I'm kind of assuming that your motor is a 2 cylinder OMC. Is this correct?

If it is and the spark plugs are above the center of the cylinders it is a 22 hp. If they are below center and you have to access them from below it is an 18 hp. Other than this and the advance weights and springs in the timer, both engines are identical in parts and construction. Cushman used a one cylinder version of this motor for one of their scooter models too.

I'm still working blind here. How about a scanned copy of your schematic.

Charley