I have a 1987 W100 custom Dodge Truck. 318 2bbl automatic. Truck started fine. Turned the key to shut it off and it kept running (not dieseled), kept running. My first thought was Ignition switch was bad, but i installed a new one and no change. I also changed my alternator because i noticed the plastic bushing on the back was gone and the power coming out was grounding.
I am lost to why i cant turn off the truck. I wonder if something with the alternator shorted out something and that is why. There is a box mounted on the back firewall behind the distributor that has a plug on it. The plug has 2 round male and the box has two female. I thought it was the control module, but when i went to pick up a new one, it didnt match. I know if i pull the plug while the ignition switch is on the truck continues to run. If I turn the key ignition off and pull this plug it kills the truck, but a vaccum relay clicks like a turn signal.
Now one other thing. If I turn the key off and pull the positive battery cable off, the truck shuts off. If the battery cable is left on after the engine shuts off, it kills the battery over night.
That happened, and also a plastic vaccum in line on the heater hose cracked (have no idea what it was, just bypassed it). This all in one afternoon on New Years Day. I ended up in the parts store parking lot and had to get the truck towed home.
I asked if there was a tall cliff nearby. Would have been easier and cheaper to just let it roll off! Anyways, I love my truck so i need some help.