Fuel pump fuse keeps blowing and truck wont start

This 30 amp fuse, If it blows when cranking, it is usually the starter dragging, if it blows by just turning the key on it is usually the fuel pump drawing too many amps.
I hope this helps.

The fuel pump is burned out or a wire is shorting to ground. If the car was working fine then the fuse burned out then it is probably the fuel pump..

This normally happens due to short in the wirings.Or if someone has connected a stereo or some other electrical contrivance to the wiring harness (bundle), either under the dash or under the hood.To confirm this unplug the fuel pump wiring connections and insert new fuse.Then start the car and see,if still the fuse blows then its a short in wiring.But if the fuse does not blows then its faulty fuel pump relay or faulty fuel pump itself.So first replace the fuel pump relay and see,if the fuel still blows then its faulty fuel pump.But if the fuse not blowing then relay was the faulty part.The fuel pump relay located on the fuse box under the hood.---------This troubleshooting tips will help you locate the fault and solve it.-------Thanks.Helpmech.

If it is blowing the fuel pump fuse, then when replacing the fuel pump one of the wires are pinched. Check the wiring. Even if the fuel pump is bound up or something then it still would not blow the fuse. More than likely the hot wire to the pump is pinched and grounding out.

shorted wiring most likely at the tank

Usually if a fuse blows when applying something else( brakes) indicates they are on the same circuit. Verify the brake lights don't work when the fuse is out or blown. If lights still are working then it's probably not related. If on same circuit then the extra load of the brakes is enough to blow the fuse. Insure you are putting in the correct fuse. Also, this indicates you fuel pump is in a strain either due to restricted fuel filter or worn pump. Replaceing the fuel filter now will only buy you a little time before the pump goes on out. It's blowing fuses because it's drawing more amps in order to run, but always replace filter when replacing pump.

use a timing light to test for spark
have spark: timing belt broken

You have a short (bear wire) somewhere. Trace the wire and find it.
Have a great evening

I had the same problem. I had to put in a 22 gage fusable link. It had burned out. I first thought it was the fuel pump.

check the fuse box under the hood and make sure the fuel pump fuse is not blown.
if the fuse is blown, replace it and see if you have any fuel/spark. the fuel pump fuse controls almost everything electrical under the hood. if the fuse keeps blowing, then there is a short sumwhere in the engine wiring harness.