Test B - Vehicle Battery
To prevent replacement of good components, be aware that the following non-EEC related areas may be at fault: battery cables and ground straps, voltage regulator and alternator, and ignition switch.
- Power Check: With ignition off, install breakout box. Using DVOM on 20-volt scale, measure voltage between pin No. 1, ignition switch (Black wire) and battery ground. Also measure voltage between power relay (Blue wire) and battery ground on vehicles built after 11/2/87. Measure voltage between power relay No. 1 (Blue/White wire), power relay No. 2 (Blue wire) and battery ground on vehicles built before 11/2/87. If reading is greater than 10 volts, proceed to step 3). If reading is 10 volts or less, proceed to next step.
- Check for Opens: Install breakout box and remove 30, 60 and 80 amp fuses. Disconnect battery. Using DVOM on 200-ohm scale, measure resistance between battery and 30, 60 and 80 amp fuses. Also between 60 and 15 amp fuses, and both relay (Blue wires) on vehicles built after 11/2/87. Measure resistance between 30 amp fuse and relay No. 1 (Blue/White wire), and 30 amp fuse and relay No. 2 (Blue wire) on vehicles built before 11/2/87. If resistance is greater than 5 ohms, repair open in wire(s) in question or replace main fuse block as required. If resistance is 5 ohms or less, proceed to next step.
- Relay Ground Check: With ignition off and DVOM on 200-ohm scale, measure resistance between power relay (Black wire) and battery negative terminal on vehicles built after 11/2/87. On all others, measure resistance between power relay No. 1 and No. 2 (Black wires), and battery negative. If resistance is 5 ohms or more, repair open Black wire in question from power relay(s) to ground. If resistance is less than 5 ohms, proceed to next step.
- ECA Ground Check: With ignition off and DVOM on 200-ohm scale, measure resistance between ECA case, pins No. 49, 46, 20 and 40, and battery negative terminal. If resistance is 5 ohms or more, repair open in wire(s) in question from power relay(s) to ground. If resistance is less than 5 ohms, proceed to next step.
- ECA Ground Fault Isolation: With ignition off, install breakout box. Unplug harness from ECA. With DVOM on 200-ohm scale, measure resistance between pins No. 46 and 49, pins No. 46 and 20, and pins No. 46 and 40. If resistances are less than 5 ohms, ECA is okay. Repeat QUICK TEST . If resistance is 5 ohms or more, replace ECA.