Theres 4 wires, labeled A,B,C and D. They should be labled on the plastic piece. If not, let me know.
Wire D is the MAF SIG, or Signal to EEC-IV module.
Wire C is the MAF return or Signal return.
Wire B is is the vehicle power ground.
Wire A is the VPWR, or vehicle power.
1) Test VPWR and Ground:
With key off, disconnect MAF connector
- Connect DVOM (digital volt ohm meter) between VPWR and GND at harness connector
- turn key on, leave engine off
You should have 10.5 volts or greater.
If not, theres a fault in VPWR ciruit or in GND circuit to battery.
2) MAF circuit short to ground:
Key off
Connect DVOM between MAF SIG and MAF RTN, and MAF SIG and GRD at harness connector
Results- 10,000 ohms or greater
if not, fault in wiring to control unit or faulty control unit. (EEC-IV)
3) MAF sensor voltage
MAF sensor connected
- backprobe MAF sensor connector between MAF and battery negative(-) terminal
Engine running
0.2 to 1.5 volts dc
If not, MAF sensor may be faulty
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2002 GT
1993 GT (SOLD)
'93 Mustang GT
RHC member #142
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