Where to wire electric fuel pump?

[HerbertPhillips]

I bought a 1975 that has not run since 2001 and put a new carb on it. It runs well. I'm using an electric fuel pump with about 6psi. Where under the hood would be a good ignition on power source? (switched by the key in run position)

 

[57baja]

I bought a 1975 that has not run since 2001 and put a new carb on it. It runs well. I'm using an electric fuel pump with about 6psi. Where under the hood would be a good ignition on power source? (switched by the key in run position)

Grab a test light and cycle the key to locate a 12v switched power source. Read electric fuel pump instructions to see what size fuse/relay to run wherever you tie in for power. I'd try the starter relay on the passenger wheel well. Should have a post labeled "i" for ignition that should be 12v switched power. Don't use "s" post that's for starter only juice when key is in start position.

 

[Oldtimer]

"I" post will only have 12v when starter is turning. The rest of the time it will have coil voltage, which is lower (9ish ?) due to resistance wire (ballast resistor) in stock harness.

 

[Madgyver]

run a key-on relay with a switch on the ground lead, Hide switch under dash. It is your theft deterrent. mount close to rear tank inlet on framerail

 

[Chiclassics]

You can use positive end of ignition coil

 

[gnpenning]

The coil positive will drop voltage in run. Same as the I post on the starter relay.

 

[Jetfixr320]

To be safe incase of a accident/rollover you should wire in a inertia switch or power a relay off of the oil pressure switch.

 

[Chiclassics]

The coil positive will drop voltage in run. Same as the I post on the starter relay.

I have been running like this since 3 years no issues. Ill check voltage there next time i get a chance

 

[ntsqd]

As mentioned above, use a relay. Source power from the battery thru a breaker or a fuse. Turn it on/off with an IGN source (other than the coil + terminal), and run that wire thru an inertia switch or an oil pressure switch.

For an oil pressure switch, this one is my own preference: https://www.summitracing.com/parts/crt-a68301 The third terminal on it is connected to a start signal so that the pump will run while cranking.