Need Quick Help With 92 Gt Maf Wiring

Discussion in 'Fox 5.0 Mustang Tech' started by Green 94 5.0, May 30, 2013.


  1. Green 94 5.0

    Green 94 5.0 Founding Member

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    I am almost done wiring up the new PMAS MAF in my 92 GT. The thing that strikes me as odd is that on the wire for the MAF return I am seeing 5v KOEO. Is this normal? We have already tested continuity on pin 9 of the EEC to verify it is the right wire. Any help would be greatly appreciated.
  2. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

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    You always measure between pins on the MAF, not pin to ground. The MAF circuit uses a differential ampliflier circuit which uses the difference in voltage between the two outputs to determine what the signal is.

    Measure the MAF output at pins C & D on the MAF connector (dark blue/orange and tan/light blue) or at pins 50 & 9 on the computer. Be sure to measure the sensor output by measuring across the pins and not between the pins and ground.

    The figures below are approximate outputs with a stock system. Your results with aftermaket parts may be different.

    At idle = approximately .6 volt
    20 MPH = approximately 1.10 volt
    40 MPH = approximately 1.70 volt
    60 MPH = approximately 2.10 volt
  3. lxman

    lxman Member

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    I post info up on here yesterday check it out bud!
  4. Green 94 5.0

    Green 94 5.0 Founding Member

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    You guys are lifesavers. The voltage was perfect when measured across pins. Seeing +5v on the maf return just made no logical sense to us and I do have an electrical problem somewhere in the wiring that is causing battery drain when the car is off. I just wanted to be sure I didn't accidentally stumble across the problem wire. Thanks for the help guys.

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