1995 Ford F-150 Mass air flow

What is the vehicle vin? That voltage may come from power relay. When you unplug sensor, the computer may have used default maf signal. I believe that relay should energize when you turn on the key. There are several systems that use that same voltage. You may have to do continuity test on wire for maf voltage. I know you jumped voltage to that circuit, maybe no signal is better than faulty signal if the computer uses a default value.

What was the actual code #, I guess I can look it up? I can only talk to you about the basics. The expert title under my name, I think refers to how many questions I've tried to answered and not my expertize.

What is your vin? I looked up vin n for your year--make--model and engine size--automatic. Voltage from load side of that relay is 12 volts and goes to several systems besides the maf. Ref voltage won't come from a relay in my opinion, ref voltage comes from computer.

It is possible I was looking at wrong wiring diagram?

My thought was maybe a faulty maf sensor? Don't replace anything unless testing points you in that direction.