Electrical wiring (fuel pump with relay and toggle)

But only if the "run" terminal is not dead when the key is in the "start" position like the one the op was going to use. (ign, gauge, bat, acc, and start are some more common switch markings)

I use OHM's law at work all the time. It doesn't apply here. When autos changed from 6v to 12v they kept the same switches and used the extra current capacity to run more "bells and whistles". A 12v low impedance coil still draws more current than the old 6v coils and we don't even know what the op has in his car.

How do you test your switches? An ohm-meter doesn't put a load on them and can make those worn pitted contacts appear brand new but they still can fail in use.

Neither one of us knows what kind of "bells and whistles" the OP has on his car (streetrod?) and what we run on our cars doesn't apply to everyone else.

 

I agree with tooljunkie....Must have safety device,..oil press switch, and / or "rollover" switch !!!

4TTRUK

 

Since the 40 Mercury uses a starter button unlike the modern key switch that you desribe, I don't think your point is relevant. We will just have to agree to disagree. I don't like to argue. I'm done.

 

What is bad about running a inertia switch?? Obviously it is better than having nothing, but do the Ford fuel injection cars that run these things also have a oil pressure switch that cuts the fuel pump off or does the computer shut power off if engine dies??

I'm putting an electric fuel pump on a '69 mustang and I want to be safe..........

 

Can you give us a part no. and brand (and maybe a pic) of the pulse trigger switch you are talking about here. That is exactly what I am looking for.

 

There have been thousands of cases of Ford inertia switches "nuisance tripping" from minor bumps or even bumpy roads. The way most hot rods ride, I just wouldn't want to worry about it. The oil pressure switch is a perfectly safe way to shut the fuel pump off automatically.

 

Reviving an "old thread", get some ideas.
Week or so back my fuel pump on LA 318 in 55 Fargo crapped out. I got home right into driveway after being 5 miles away on the highway and sensed fuel starving issues.
Being a weekend in rural Canada, no way 4 me to go buy an overpriced fuel pump from local parts. Rock Auto 3 to 5 days wait and I needed truck running, like now.
So bought Facet Gold flo 4 to 5.5 psi electric fuel pump locally at Princess Auto ( Canada's HF sorta).
I installed right at rear of gas tank, plumbed, wired etc.
Truck fired right up, great works well. Buttoned up what the install entailed. Time for test drive, back outta garage leaving trail of gas.
Stop and see, fuel pouring outta old mechanical pump weep hole.
Bypass mechanical pump, go for short drive, works great.
Okay so, pump wired from, key on fuse panel to Fomoco Interia switch to 20 amp toggle switch, 14 gauge wire to fuel pump, which has a 1.8 draw.
Now my old tank has no return line, not ideal.
After all this, might just order a new mechanical pump and install.
Use electric pump on a tractor or use for priming 318s carb.