Ford Excursion, Expedition, Lincoln Navigator 2000-2005

Power And Ground Circuit Checks


Measurements made at the BOB are accomplished via test leads and probes from the DVOM or a Lab Scope. If any of the terminals on the PCM or BOB are damaged or loose, test measurements made at the Breakout Box will be inaccurate. To verify the PCM battery power (KAPWR and VPWR) and ground circuits (PWR GND) are normal (correct) at the BOB, test the condition of the circuit between the battery negative (-) post and these circuits prior to starting a test sequence.

With the key on, the voltage drop from the battery positive (+) terminal to KAPWR or VPWR at the BOB should be less than 0.1v. The voltage drop from the battery negative (-) post to PWR GND at the BOB should be less than 0.1v (key on).