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ColoradoHawk
06-15-2018, 02:16 AM
I’m getting ready to install an electric fuel pump in my ‘63 Hawk. I’ve decided to use a Holley Mighty Mite (part# 12-426) and was planning on using a Summit Racing fuel pump relay kit (part# SUM-890023) which includes a 30 amp circuit breaker. My question is, is 30 amps too high and would 15 amps be safer? I’m not very knowledgeable when it comes to this and I want to do it correctly and safely.

graylark
06-15-2018, 03:20 AM
The Holley installation instructions call for using a fuse rated at 3 to 5 amps.

TWChamp
06-15-2018, 06:37 AM
Electric motors have a high amp load when they start, so either use a slo-blo fuse or one of high amp capacity.

wittsend
06-15-2018, 11:56 AM
If you are going to rely on the the 30 amp breaker then you had better wire the pump in with #10 wire (or larger..., which would be a lower number) and I wouldn't really recommend reling on a 30 amp breaker if as someone esle stated the pump itself is rated at "3 to 5 amps.".

One of three things is going to be the "fuse." The wiring, the pump or a fuse/breaker. The wire is not ideal as it can cause fire and damage other wires nearby. The pump (let's assume it is clogged) might be rescued before frying by removing the obstruction. Therefore a fuse is a cheap item to protect the wire and pump. Chose a fuse that is equal to the stated rating of the pump but make sure the fuse is rated below the rating of the wire.

jrlemke
06-15-2018, 04:10 PM
Most factory installed automotive electric fuel pumps that I have seen are fused at 10 amps.Not sure about after market. The one on my Hawk has a 10 amp fuse. I've had no problems in 2 years. I mostly use it for starting. -Jim

Ron Strasser
06-15-2018, 05:10 PM
Coloradohawk;
Holly's instructions say to install a 3 amp fuse in line to the pump. You can leave the 30 amp fuse or circuit breaker in the line. As long as the 3 amp fuse is in the line going to the pump all is good.
You should also fuse the pilot circuit for the relay.
You need an inertia switch (as in new cars) and or a oil pressure switch. Both of which stops the pump in case of an accident. My Ford Bronco has a inertia switch and the Diesel Chevrolet has a oil pressure switch. Both built that way by the factory.
Ron

ColoradoHawk
06-16-2018, 01:56 AM
I thought that 30 amps was way too high! I will then just not use the supplied circuit breaker and use a 5 amp fuse instead. I’m going to install both the oil pressure switch and Ford inertia switch, and after looking the wiring diagrams over and over and over again, I’m pretty confident I understand how everything goes together.

JLB
06-16-2018, 05:12 AM
Coloradohawk;
Holly's instructions say to install a 3 amp fuse in line to the pump. You can leave the 30 amp fuse or circuit breaker in the line. As long as the 3 amp fuse is in the line going to the pump all is good.
You should also fuse the pilot circuit for the relay.
You need an inertia switch (as in new cars) and or a oil pressure switch. Both of which stops the pump in case of an accident. My Ford Bronco has a inertia switch and the Diesel Chevrolet has a oil pressure switch. Both built that way by the factory.
Ron

You can pick up an inertia switch at a Pull A Part lot. I get them from Crown Victoria's, Grand Marque's etc.. Usually located on the left side of the trunk, behind the molded panel. Cost is $6.00 here in Louisville. I wire them with the ground wire going through the inertia switch.
John

chet445
06-16-2018, 08:38 AM
I am the process of installing electric fuel pump on '62 Hawk. What type of accident would cause need for inertia switch or oil pressure switch? a wreck? anything else? What else could require shut-off of pump? Thanks, Chet445

TWChamp
06-16-2018, 09:33 AM
Any kind of accident that opens up a fuel line to let gas flow will need a fuel pump kill switch.

64V-K7
06-16-2018, 09:51 PM
You have an Oil pressure cut-off switch, which is surpassed in viability by the inertia switch. The OPSW only stops the power to the pump when the oil pressure goes below 5psi. The inertia switch just needs a bump to kill the power.