rewiring a 1988 ranger ecu

[ibdalovely1]

so ive found a couple good schematics showing all the pinouts on the ecu but im not totally sure where i hook the power and grounds im basically making a standalone harness using the oem one trying to delete anything not needed in the harness as well any links to info would be greatly helpfull

 

[rusty ol ranger]

so ive found a couple good schematics showing all the pinouts on the ecu but im not totally sure where i hook the power and grounds im basically making a standalone harness using the oem one trying to delete anything not needed in the harness as well any links to info would be greatly helpfull

Everything in the factory harness is needed.

 

[Nez'sRanger]

Your best bet would be to get the evtm for your model year, and make a good list for your ECM. I had to do that with my 89. The list I found on the tech article for a 2.9 MAF conversion was taken from an 86 or 87, and I noticed several differences from mine. Best to have your year's evtm.

 

[RonD]

Pins 16, 20, 40 and 60 are Grounds

Pins 37 and 57 are Key ON/START 12volts

Pin 1 is for KAM(keep alive memory), it should have 12volts all the time, like for clock or radio presets, it holds "learned" settings like air/fuel offsets and idle voltage for IAC, it won't drain battery.

Pin 17 is for Check engine light(CEL) or malfunction indicator light(MIL), it is a GROUND for a bulb, so bulb in the dash gets 12volts key on, PCM(ECU) grounds pin 17 on boot up as a bulb test, bulb lights up
After engine start up bulb should go off, if no urgent codes are set, codes can still be in memory and CEL won't stay on