Having problems with your 1986 Jeep Comanche ?
1988 jeep comanche will start only when you hold tumbler in the start position, when you relese it, engine stops.. engine is a 4.0 auto, fuel injected 4x4
Probably a bad ignition switch. Very common on mopar vehicles. To verify, check for voltage on the control side of the fuel pump relay with key in run position, then check for voltage at coil in run position. There should be power to both if the switch is OK.
If the car has a resistor coil with a ballast resistor to drop voltage from 12 to 8 then check the resistor wiring. When you engage the starter tumbler it by passes the ballast resistor and sends 12 volts straight to the eight volt coil to get good spark. When you release it the 12 volts goes through the resistor to 8 volts and then the coil. If there is a fault in this circuit the engine stops. Jump the 12 volts straight to the coil and start it. If it keeps going the ballast circuit is faulty. Paul
Repair Help & Product Troubleshooting for 1986 Jeep Comanche
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