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PWM valve troubles
Posted: Sat May 27, 2006 10:23 am
by mtnslide
My pwm seems to not change pulse width with different coolant temps, on the stim the FIDLE light is always fully on and does not change when i change the settings around in the PWM Idle tables. I have done the TIP121 mod and the transistor seems to be working normally. Is there anything more i can do to test the circuit without an O-scope.
Posted: Sat May 27, 2006 12:58 pm
by MegaScott
The switching time of the PWM is fast enough that you won't see any change in the LED. You can try using a light bulb as a load, and use a series 1 ohm resistor, put your voltmeter across the resistor and then vary the CLT you should see more current when cold, less current when warm. Sometimes just using a regular 12v bulb works as a load too for showing the average DC levels when PWM is turned on.