Gary57 Posted August 9, 2014 Share Posted August 9, 2014 My fuel pump runs all the time that the battery is hooked up. 1987 Comanche 4 banger 4 speed. Anyone got any ideas? Gary Link to comment Share on other sites More sharing options...
oldseddie Posted August 9, 2014 Share Posted August 9, 2014 Could be fuel line in tank on pump leaking. Link to comment Share on other sites More sharing options...
HOrnbrod Posted August 9, 2014 Share Posted August 9, 2014 You mean you can hear the pump running constantly when the battery is hooked up? Even with the IGN key off? Link to comment Share on other sites More sharing options...
Gary57 Posted August 9, 2014 Author Share Posted August 9, 2014 Yes the pump runs even with the switch off. Link to comment Share on other sites More sharing options...
HOrnbrod Posted August 9, 2014 Share Posted August 9, 2014 Only way I see that can happening is because there is a "foreign" battery hot wire run directly to the fuel pump circuit after the relay. Even if the relay contacts were shorted closed, the pump should only run with the key switched to IGN. Pull the fuel pump relay then hook up the battery and see if it runs. If not, the relay is internally shorted. If the pump still runs, I'd start at the fuel tank looking for a hot wire and work your way back. Link to comment Share on other sites More sharing options...
Gary57 Posted August 10, 2014 Author Share Posted August 10, 2014 Is the relay under the hood or the dash? Link to comment Share on other sites More sharing options...
Keyav8r Posted August 10, 2014 Share Posted August 10, 2014 Under the hood, passenger side inner fender, just behind the battery, above the ignition module. Search "relays" in the "random informative pictures thread" in the DIY forum section for a photo. Link to comment Share on other sites More sharing options...
Gary57 Posted August 10, 2014 Author Share Posted August 10, 2014 Ok I know what your talking about now, I have already changed the relay. I guess my only option is to start tracing the wires. Thanks for the help. Gary Link to comment Share on other sites More sharing options...
Gary57 Posted August 20, 2014 Author Share Posted August 20, 2014 Thanks Hornbro I had time today to check my wiring and found someone ran a wire from the fuel pump to the battery side of the fuse block. I really hate it when people try to reinvent the wiring harness. I am going to trace the wire from the fuel pump and try to find the correct wire to splice into, thanks for your help I guess I should have looked a little closer. I will not take anything else for granted when I work on this truck. Link to comment Share on other sites More sharing options...
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