fuel pump problem

2002silverado5.3 said:

so here is my issue, two nights ago i did the 6 hi mod. i grounded low beams to the frame for the high beams. then i ran a diode from the runing light fuse to the drl relay so i could use the headlight switch. all was good for 3 days. today, with no warning my truck shut off, not like sputterd down but like i shut the key off. now it will not start. and now for some reason the fuel pump relay will not 'flip/switch". also the headlight relay wont flip. is there any connection/relationship between the two? also i could not get power at the fuel pump relay socket. this is on a 2002 silverado. throw out any ideas you have because im out. also the fuel gauge says im empty so that verifies i have no power to the fuel pump.

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I have no idea what your talking about, what you did and/or the terms you use. anyway the fuel pump works like this : fuel pump relay contact 38 has power to it at all times. fed by a 20amp fuse. when you put ignition on , the PCM applies power to the coil of the fuel pump relay 85 . 86 is always ground. 87 is the fuel pump switch connection of the relay to the fuel pump.

what you may have done is damaged the PCM or you opened up some grounds. If I was doing this I would have a good meter and check for opens. also I would use a fused jumper and apply power to the fuel pump.


the fuel gauge does not have any power applied to it from the fuel pump circuit. these are different. so if the fuel gauge does not work, also then you have bad wiring or connections . when you did this wiring you soldered all your connections and used heat shrink to protect . if not then I would expect these type failures.


if you cannot check all this out best return it back to original. when you do this you will find what you did to cause this I guess. good luck .