Aerostar, Explorer, Ranger & Navajo
- When this occurs, Red BRAKE warning light will be on. Unplug electro-hydraulic valve connector. Measure resistance between valve switch pin (on valve side) and valve body. See Figure . If resistance is less than 10,000 ohms, replace electro-hydraulic valve. If resistance is 10,000 ohms or more, check resistance between valve switch pin (on valve side) and solenoid ground pin. See Figure .
- If resistance is more than 26,000 ohms or less than 18,000 ohms, replace electro-hydraulic valve. If resistance is 18,000-26,000 ohms, check resistance between valve switch pin (on valve side) and valve body, with hydraulic pressure applied for a minimum of 30 seconds.
- If resistance is less than 10,000 ohms, replace electro-hydraulic valve. If resistance is 10,000 ohms or more, check resistance between ground pin (on harness side) and chassis ground. See Figure . If resistance is one ohm or more, repair open in isolation solenoid wire. If resistance is less than one ohm, reconnect valve connector.
- Disconnect battery. Unplug control module connector. Measure resistance between pin No. 4 and pin No. 6 at module connector, on harness side. See Figure . If resistance is more than 26,000 ohms or lower than 18,000 ohms, repair open or short between electro-hydraulic valve and control module. If resistance is 18,000-26,000 ohms, replace control module.