1989-’95 Ford pickup.
A 1989-’95 Ford pickup equipped with four-wheel drive and a manually shifted transfer case may upshift to third gear under 15 mph while in two-wheel drive. This may be caused by a false four-low signal at the controller.
With the transfer case in two-wheel drive and the engine running, check the voltage at controller pin 14 on 1994-’95 7.3L Turbo diesel models or pin 12 on all other models.
If the voltage is zero, check for a faulty transfer case switch, or a damaged connector. Also check the operation of the dash bulb and the harness under the dash for a cut on the dash panel brace.
Note: An aluminum spacer washer must be installed between the switch and the case.
Technical service bulletin courtesy of ALLDATA.
For additional information, visit www.alldata.com.