fuel pump rewire question

[maddogxx]

Ok so i followed the tech post by DSM_Thunder fuel pump rewire for dummies and everything went well, except I have one question. The ground wire that is cut from harness is not used, the instructions were not clear to me. I soldered together the cut wire from the pump connector the relay and the chassis ground. Do I just tape the cut wire from the harness & not use it?

 

[ricktb]

the easiest way to explain is this.. when you turn the ignition its an on/off switch (ACC), the relay itself is an on off switch for the fuel pump. the relay has an connector when you turn the key it flips the internal switch to the fuel pump on. so the relay require 4 wires..

ACC input (ignition voltage on)
main power lead from battery (not connected to fuel pump until relay switch is on)
switched output positive lead to fuel pump positive (when relay is switched on its basically a direct connection to the battery)
negative output to chassis ground to complete the ACC circuit

the relay has a magnetic coil inside so that the acc switch turns on the fuel pump switch, the two circuits are completely separate inside the relay.

fuel pump has its own ground, or you can couple the fuel pump ground together with the ACC ground. Just put ALL GROUND TO CHASSIS. Yes you should tape cut wires
You need to figure out the exact connections on the relay housing and you can plug in the right wires.

Most basic relays have 5 connectors, one prong is to let main power flow through while the relay is in an off position.. you will not need this one at all, you should tape or cover this prong just in case of short circuit

remember to put a fuse on any power lead direct from battery, I HIGHLY recommend a 30-50 amp fuse and do not use this main power lead for anything other than fuel pump. I branched some power off the fuel pump power lead to my ignition and the 30 amp fuse melted and almost burst into flames in my engine bay.

Use 10 gauge wire for everything including fuse holder.

 

[ed1380]

@op-yes