Test FH - Wot Circuit

To prevent replacement of good components, inspect all related wiring, wiring harness, connectors and components for evidence of overheating, looseness and other visible damage. Visually inspect throttle linkage, throttle operation and WOT adjustment.

1. WOT Signal To ECA. Install breakout box. Disconnect ECA Yellow wire from breakout box Pin No. 24. Measure resistance between Pin No. 24 and ground. With the throttle released, ohmmeter should read open. With throttle fully open, resistance should be below 5 ohms. If resistance is reading correctly, replace the ECA. If resistance readings are not reading correctly, go to step 2.
2. WOT Signal From WOT Switch. DO NOT disconnect the WOT switch. Disconnect the Yellow wire from the WOT switch. Measure resistance between Yellow wire and ground. With the throttle released, ohmmeter should read open. With throttle fully open, resistance should be below 5 ohms. If resistance is reading correctly, service Yellow wire from WOT switch to ECA. If resistance readings are not reading correctly, go to step 3.
3. Signal Return To WOT Switch. Measure resistance between WOT switch Yellow/Green wire and ground. Resistance should be below 5 ohms. If resistance is below 5 ohms, replace the WOT switch. If not below 5 ohms, service Yellow/Green wire from WOT switch to ECA.