Hi
I have an electric fuel pump in my 1967 coupe, I am currently rewiring the car and want it fit an oil pressure safety switch and relay for the pump. I have a wiring diagram and can see how to wire it up. My question is where is the best place in the car to mount the relay, should it be near the battery say on the firewall then run the feed to the back of the car where the fuel pump is. Or should it be nearer to the pump in the trunk say with the long run of wire coming from the battery source to the relay ?
Thanks for any advice
Mark.

Run a good size braided wire from good power
source like the battery and run it to pump location.
Put your relay somewhere near pump but in a place where you can access the relay for servicing.
Connect power source to relay. Run per from relay
to pump. Run switch wire from relay to trigger
Location. This could be your fuse panel. Somewhere
Where you want the pump turned on.
Follow pump instructions. Probably need fuse(s)

why would you put the relay at the back neer the pump, you just have to run more wires all the way back there with more chances of them getting damaged and shorting out. I mounted mine up front and then you only have one wire to run to the pump. Has been on my car like that for 40 years with not one problem.
Just make sure you use a little bigger wire for the pump than what is recommended, and use inline fuses

Thanks for that,
I was hopping that I could mount it on the firewall for ease of access and shorter wires apart from the one that will run to feed the pump. I have got some 10awg wire for that and the instructions say no less than 14awg so hopefully that should be sufficient for the long run.

My relay is in my trunk. I ran a 10awg wire directly from the battery but I put a 30 amp circuit breaker by the battery feeding the 10 gauge wire so if the small chance the wire gets a short it will trip the breaker.

I agree. Remember why we are using a relay. We want larger gauge wire for the power wire and small gauge wire for the low amp switch wire. You don't need a big switch with higher amp capacity. I see that you have a 69 FB. Your main power source comes directly from the battery large gauge power cable. Place relay on firewall near ignition connection. Run pwr wire from main power hub (feed from starter) to then relay to pump. Run smaller wire from ignition to relay. Fuse the lines

#10 wire would be fine, just use the size fuse that is recommended for the pump.