Ground Circuit
- Turn ignition off. Locate ignition control unit in engine compartment, forward of left front wheel housing. Connect negative lead of ohmmeter to ground. Backprobe ECM terminal No. 20 (Black wire). Resistance should be zero ohms. If resistance is not zero ohms, repair open to ground. Harness grounding point is located on engine lift bracket.
- Connect negative lead of DVOM to a good ground. Backprobe ECM terminal No. 20. With vehicle running, DVOM should indicate less than one volt. If voltage is higher than one volt, check for open, corrosion, or loose connection on ground lead.