So i ran into a little problem with my return style fuel system. The fuel pump on my 1989 mercury grand marquis is still running after turning the ignition off causing the battery to drain.
2011 Dodge Caravan Fuel Pump Relay Bypass Instructions
Fuel pump keeps running with key on. If everything works correctly key shuts motor off kill switch shuts motor off and fuel pump runs when its supposed to then its the alt. Turn the key to the on position without starting the engine. Start the engine take off the fuel pump relay and leave the engine stop itself when this occurs turn off the key the you can take off the filter and changed it. To do that first find the fuel pump relay in the main fuse box located in the engine. I suggest you check the net for info on how a fuel pump relay works and conduct the electrical test. It sounds like you have a short to voltage somewhere.
Once you located open the fuel door and take off the cap and leave it open. If it is stuck the pump could continue to run. This primes the gas to the injectors when doing this. If the pump runs with the relay removed its not the relay. Sounds like the fuel pump relay in under hood fuse box try finding another next to it thats the same from the headlamp relay and swap them and see if it helps. That makes sense to me im going to try that tomorrow.
Is it possible there is a short in the ignition system or is this a sign that the fuel pump is going out. If not heard running check the oil pressure switch for the 12 volts needed to run the fuel pump starts there on that harness. It wont turn off and it keeps running even with the key is off. A full explanation of how the relay works and how to check it is quite long. You should hear the fuel pump running for 5 seconds if working. Normally the fuel pump relay operates during starting and when turning off the engine.
Replacing the fuel pump relay stops this from happening for a short time but it soon reoccurs.
Gallery of Fuel Pump Keeps Running With Key On
