I need suggestions for a diode or some type of one way “valve” for a wire in my car. I recently wired up a fuel pump relay with 2 power sources to control the relay. But I need suggestions for a diode to add to one of the wires to prevent backfeeding. I used a zener diode with a Vz of 12v but it burned up. I'm now looking to get some rectifier diodes with a rating of 100v and 1amp, correct if im wrong but that wont work bc car batteries run very high amps. I'm looking for suggestions, thank you for all replies!

 

1N4002 volt is a 1 amp 100 volt diode.
1N4003=200V
1N4004=400V
........
1N4007=1000V

 

You need two diodes, one for each source feeding the relay. 1N4007 is good enough.

 

I'm now looking to get some rectifier diodes with a rating of 100v and 1amp, correct if im wrong but that wont work bc car batteries run very high amps. I'm looking for suggestions, thank you for all replies!

Correct, a car battery can deliver very high amps but the current through the diodes are limited by the resistance of the fuel pump relay which must be below 1 amp.

 

Your relay coil is probably going to draw less than a 1/4 amp, so a 1A/100V diode is plenty big enough.

Most vehicle relays will operate fine after the voltage drop of a standard rectifier diode, so schottky diodes are not necessary.

 

Sounds good! Thanks everyone for the replies.