Near Intersection of I-35 & I-90 Southern Mn. | Before your attach the wires from the Ag Leader module to your PWM valve, I would just ry to run the valve from another 12V source. Remember PWM just sends short "shots" of 12VDC to the valve. It send sends a "shot" following by a pause of no current. This ON/OFF business is done very fast like 100 times/second (100 Hz). The ratio of the time ON versus the time slice (1/100 of a second as an example) is called the Duty Cycle. This could range from 0% (valve closed) to 100% (valve fully open). Normally you would be operating somewhere in between if everything is matched up properly. This may involve some trial & error of pump stroke setting/drive sprockets, tractor hydraulic flow etc. but first I would just try to get it going.
What I'm getting at is once you have the hydraulic plumbing, chains etc. all set up, I would activate your hydraulic system with no wires attached to the PWM valve. The valve should remain closed, so no oil, no pump rotation. Then using a separate 12V source and ground connect the PWM valve, The valve should go fully open producing maximum oil flow and maximum pump speed. Your pump should have a water source so it isn't being run dry.
This should give you an idea of the maximum speed available. You may find that your max speed is too slow to attain your target rate. Changing the pump stroke, sprocket drive, hydraulic flow etc. can help. You may find that your max speed is too fast. Changing the sprocket drive etc. can help there.
Next I would test the Ag Leader to see if it is set up properly by using a meter. I would create a test configuration to test the PWM output before actually trying to use it. You will need to have a jumper on the implement switch branch. When creating the configuration change the control type to 12V PWM. Choose a product and observe the target rate. It will be zero if this is a new product. Enter in a target rate. Connect your meter to the two leads which will eventually go to the PWM valve and set the meter for volts. Flip the Master switch ON and observe the voltage on the meter.
It may be zero or show some value. Put the rate in "M" for Manual. Now when you push the UP arrow key the voltage on the meter should increase. You should be able to get it to increase to about 12V. Pushing the DOWN arrow key should cause the voltage to decrease. When you release the UP or DOWN arrow, the voltage should stay steady on the meter. What should be happening is you are changing the duty cycle which your meter will show as an average voltage. If you are able to get your meter to behave this way, the configuration is likely correct. If you are not able to get your meter to behave this way, there is no point in connecting the PWM valve since it will not work
Hopefully you will be able to get each of the separate tests above to perform properly. You should then be ready to connect the wires to the PWM valve and do some further testing with water.
Normally the wires are just connected directly to the PWM valve from the module but if you are skittish about this, I guess you could install a fuse in each of the wires for your initial testing.
A bit of concern is that your PWM valve seems to indicate that it might draw 1.4 Amps. I'm not certain of the maximum output that the Ag Leader module can deliver. I know from experience it can run BRAND PWM valves directly.
The PWM output from the Ag Leader module does have its limits. I'm not certain what they are, Your valve might be too much, I just don't know.
The Ag Leader module can be used to run a 12VDC motor directly if the motor load is small. Generally running a 12V fertilizer pump exceeds the capacity of the Ag Leader module so a motor driver is necessary. A motor driver is an electronic device which goes between the Ag Leader PWM output and the motor or device requiring a high current PWM source. The motor driver is connected directly to the vehicle battery. It produces a high current PWM output based on the low current input it receives from the module.
Hopefully this is not required in your case with your PWM valve since it would add complexity and extra cost to your project.
Edited by tedbear 5/11/2025 06:56
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JD PMW Solenoid pinout (hyd drive from a 1770)
