Farms With CASE - 5/14/2022 22:10
The impeller spins very easily by blowing through it but I am not sure how to test if it's sending signal to the computer to then command pwm valve. Flow meter is a year old but could have failed and I stated that several times. But that still doesn't explain why the fert pump runs at a normal speed with vac fan off but overspeeds with vac fan on. Did determine there is 500 psi in the pressure lines with vac fan off and jumps to 2500 psi with vac fan on. I couldn't see anywhere where pressure would be reduced going to fertilizer pump motor but thought was maybe its getting over pressurized. Even more weird is if you pull vac fan pwm coil off the stem so motor doesn't spool at all the fert pump runs normal.
I'm leaning towards a bad flowmeter but the direct tie to a spinning vac fan is just odd.
Is the PTO powered hydraulic system a PFC system? Kind of sounds like turning on the vac fan is causing the hydraulic pump to 'stroke' & have more output (which makes sense) but the control valve for what goes to the fert pump won't throttle back to get right pump output. One thought would be could you run some other hydraulic load on the hydraulic system to see if it causes the same fert pump problem? | 
$100 to first right answer/ Case 1200pt fertilizer pump issue
