my 85 720 no fuel replaced relay

[tyraken]

i bypassed the relay for awile and it ran. once i bought a new relay and plugged it in it died. i dont know what the relay does so i can figure out the problem. please help!

[zanegrey]

either the fuel pump is failing .
or the power wire is grounding out back by the tank itself.

[12Ounce]

When you "bypassed" the relay ... I think what you were doing is jumping the contacts together. This would cause the same effects as a functioning relay that is energized.

When you replaced the jumper with the relay you don't get the same results: (1) because the relay is not being energized, i.e., no voltage across the coil, or (2) the relay is energized, the coil is moving ... but the contacts are bad. Or, (3) something very similar.

Do you ever feel or hear the relay "click"? ... this is the coil moving ... doesn't necessarily mean the contacts are working. ... but does mean you're getting the voltage to the coil.

[tyraken]

Originally Posted by 12Ounce

When you "bypassed" the relay ... I think what you were doing is jumping the contacts together. This would cause the same effects as a functioning relay that is energized.

When you replaced the jumper with the relay you don't get the same results: (1) because the relay is not being energized, i.e., no voltage across the coil, or (2) the relay is energized, the coil is moving ... but the contacts are bad. Or, (3) something very similar.

Do you ever feel or hear the relay "click"? ... this is the coil moving ... doesn't necessarily mean the contacts are working. ... but does mean you're getting the voltage to the coil.

i do hear A clicking noise but its not the relay. it comes from the engine. all in all my dad is going to help me rewire the entire truck. we just need to find the time. i got it jury rigged right now, it runs. thats all i really wanted for my first car. thank you for all the help i will check the contacts and the coil. oh and the fuel pump is new. not even a month old.