front mounted fuel pump wiring

[kp4058]

As I relocate the fuel pump to the front, where do I draw the 12v power from? The bottom of the relay panel or elsewhere?

[justjoel]

I just did this myself. I ran a new power wire from existing wiring harness through the tunnel to the front. I believe it was a brown wire on the original harness and I grounded the fuel pump to a common ground for the headlights. Be sure to use rubber grommets when going through any sheet metal though.

Additionally if you're carb swapping you'll need to ground the pin on the relay board so the pump runs when you turn the key on. There is logic to run the pump for a few seconds with the fi brain that you will be bypassing without the fi in place. Figured that out after a bunch of troubleshooting.

[John Rogers]

I would say it depends on what you are going to use the car for? If a track/auto-x car many folks remove the key start switch and install a kill switch and also a push button to crank the engine. If you want to keep the key then tap into one of the wires from the back of the key so that the pump gets power when key is on. Most auto parts stores sell wire, lugs, tee-wire connectors and it is easy to do. Here's a picture of what I did to my 914-6 and there is an additional starter in the engine bay so I can start the car from outside and look for leaks.
John Rogers the oldracer

[kp4058]

What size fuse would be appropriate for the Bosch pump?

[Dave at Pelican Parts]

Originally Posted by justjoel

I ran a new power wire from existing wiring harness through the tunnel to the front. I believe it was a brown wire on the original harness ...

In our cars, brown is always ground! Unless someone monkeyed with the wiring, at least.

Fuel pump power would be black/red--black with a red tracer stripe.

--DD

[justjoel]

Dave,

You're right. The brown wire was abandoned in the rear harness. My fault.
I tapped into the black/red and ran a new red wire to the frunk for the fuel pump and ran a new ground wire to the headlight bucket on the passenger side.

[Brookshire my]

What ever you decide to do be sure the hot wire to the pump has a fuse in line somewhere.

[kp4058]

The replacement pump is a Bosch unit with one inlet and one outlet, no return function. Which end is the inlet, the larger or the smaller?

[Dave at Pelican Parts]

The larger should be the inlet. Is there a label anywhere? If it's just a letter, then "S" is the inlet (I think it's for "Suction") and "D" is the outlet (that is for "Druck", which is "pressure" in German).

--DD