1994 Ford F-150 ABS module shorts out

1994 FORD F-150

250,000 MILES • V8 • 4WD • AUTOMATIC

DPDERMOTT

MEMBER
1 POST

I removed/replaced instrument cluster to replace bulbs. I also removed/replaced ABS ECU module to run antenna wire. Now the ABS ECU module shorts out, the trans shifts HARD, and the speedo doesn't work. I put in another ABS module and everything works fine for 1-2 minutes until the replacement module frys. I can not find a wiring diagram in my haynes manual for the ABS module. I can live without abs, but the shifting and instrument cluster I need!

Oct 30, 2010 at 5:25 PM

KHLOW2008

✓ASE Certified Mechanic
41,814 POSTS

Hi dpdermott, Thank you for the donation. When the speed sensing circuit fails, the speedometer would not work and that would result in harsh or erratic shifting. Symptom description indicates the work performed had resulted in a short in the wiring circuit and the most likely wire would be the Light Green/Black or Red/Pink wire. You would have to rework back from where you did repair work and check if any wires are pinched or shorted to body.

The image is not very clear here so I have followed up with a pdf file of the schematic to your email. Let me know if you require anything else.

Mar 10, 2021 at 12:59 PM

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