FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

Chart No. 1, Control Unit Power Supply Circuit Test

When the ignition and main switches are in the On position current flows to the ignition switch, fuse 11 of the junction block, cruise control switch, control unit and to ground.
Check ECU terminal No. 7 on 1990 models or terminal No. 2 on 1991 models, control unit power supply. When the cruise control main switch is on. Voltage measured should be approximately 12 volts.
Check ECU terminal No. 10 on 1990 models or terminals No. 8 and 14 on 1991 models, control unit ground. No voltage should be present.