Rear Fuel Pump - Voltage Fluctuation

[kostya.lyt]

Hey guys,

I've been chasing my tail with fuel pump related problems for a while now. Initially, I ran two separate fused wires directly to the battery to avoid any issues with the single 25A fuse (5k miles). At some point, I had to replace the relay for the rear pump after the tell-tale signs of high idle and rich mixture. Just recently, the issue came back and I found the relay plastic melted. Also, for the record, both pumps were replaced 5k miles ago.

The issue I'm trying to figure out is why the voltage at the pump isn't stable at 13-13.5V. Based on the wiring diagram, the WUR gets the voltage from the rear pump circuit, could the wiring and/or the WUR be causing this?

Overview:

- Car off - Zero resistance between terminal 87 and positive cable at pump
- Car off - Zero resitance between ground cable at pump and battery ground
- Car off - Relay terminals jumped - 12.6V stable at pump
- Car on - Relay terminals jumped - voltage fluctuates
- Car on - Relay installed - voltage fluctuates

VIDEO: https://youtu.be/4cYObGelBUE

Thanks in advance!

[T77911S]

check the voltage at the battery with the car running.
clean both battery terminals.

the way I split my power and put it on 2 fuses looks factory. in fact, you cant tell its been done unless you start tracing wires.
what I did was cut the wire at relay 1 pin 30 AT the relay. then I simply ran it over to the bottom of an unused fuse. then I ran a red wire form the top of the fuse for the original relays over to the new fuse for relay 1. very simple to do.
problem is figuring out which wire at the relay is going to pin 30.