Need Quick Help With 92 Gt Maf Wiring

Green 94 5.0

Founding Member
Mar 25, 2002
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Ft. Lauderdale, FL
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.
 
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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
 
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.