I am having my AFM flowed at Pro-Flow to a calibration curve (i.e. volts. vs. lbs/min). Car is a 1981 US and will be getting a MAF hot wire conversion.

I was under the impression this was a 6.5 volt system, meaning max deflection of the flap sent back 6.5 volts to the L-jet brain. Most of the newer cars are 5 volt systems.

My question is this, how do I bench test the AFM? I have been able to supply 12 volts to the AFM and get a signal back, but something tells me this isn't right, since I get a voltage signal back which can go nearly as high as what I supply to the AFM (when plate is max deflected).

What is the AFM spply voltage, and where is it supplied (i.e. what pins)? I have a factory service manual, but this information is not provided. I thought the AFM was provided with 12 volts, but perhaps I am wrong on this...? Is there a resistor somewhere which cuts voltage the AFM sees?