Mpatch

If you look up dtc for mass air flow sensors you can see from their failure modes what the ecm input is supposed to be P0102 and P0103

Sorry, typically from what I remember. The third wire is typically the signal wire. You get the 12v in then ground and the 3rd wire the ecm will read the signal via voltage drop usually.

This is more of a personal curiosity rather than helping you.

From what I can make sense, the way this thing would work is by heating up an element. The air flow will cool the element, and the ECM measures the current needed to keep the element at a pre-set temperature.

Would that be correct?

Look every one, we have a fucking retard amongst us.

Yup first thing I did. Stuff the compressor tanks in the rafters and ran plumbing back to the pump and motor on the ground. In a cabinet. Best thing is that the extra plumbing acts as an air cooler helping remove water from the air.

Okay this is fun. So first of your amp reading is no Bueno. As I can tell you have no real load on the circuit so your amp draw will be low. Until something acts as a load like a light bulb contacting the frame and the neutral line or your hands. So the amp will rise.

Now the next thing there is power going to the motor, with out the foot pedal engaged?

A quick hunch makes me say is the new foot pedal wired backwards? On ac circuits it’s you cut power at the switch and the rest of the unit is connected to neutral line all the time.

Those sowing machine motors are typically “universal motors” they are brushed motors that can run on both ac and DC. So power flows from footpedals to brushes to armature, to windings back out the other brush. It’s a bit on the weird side that the shaft has voltage. It could be from a brush sitting funny maybe. But I would most definitely just check the wiring orientation for starters. Then go from there. Adding a ground connection isn’t a solution. A ground wire is to prevent you from getting hurt when this happens.