Need '84 911 Fuel Pump Help !!

[GWA911]

“The fuel pump stopped working.

The trouble shooting lead us to the wire from the relay to the fuse block. When we run a wire wrapped around terminal that sends to the fuse block and then attached it to the fuse block the fuel pump started and the car would run. Without the jumper there was only 3 to 5 volts at the fuse block. I have several questions about this (wiring for me has always been my week point… it took me two hours to trouble shoot this and that was with the book!):

1. What would cause such a low voltage reading at the fuse block? I was thinking maybe a short.
2. Where would be the most likely point of the short (I was thinking I should try to repair it first)?
3. Since I do not want to purchase a new wiring harness, what is the gage of wire I should purchase to run myself?
4. Should it be run to the top of the fuse block or bottom? The jumper wire I ran to the top of the block.

Does anyone have helpful answers for this ??

Thanks in advance. Glenn

[Tippy]

I would look for corrosion and loose connections on the entire circuit.

[E Sully]

The power to fuel pump does not happen till the dme sees the engine is spinning from the speed and reference sensors on the flywheel. It then energizes the dme relay. Are your speed and reference sensors ok?
If you remove the dme relay and put a jumper across pins 30 and 87b does the fuel pump energize?
I would check the voltage at both sides of the fuse block to ground, and at the dme relay pins to ground.
It is possible their is a problem with the relay, or the fuse block connections could have corrosion.