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Discussion Starter · #1 ·
Hi All - Looking for advice since this is first time wiring an electric pump. Sorted through the relay wiring which I think I understand now. However, wondering the best location (i.e. closer to the battery, firewall, or under dash) for the relay. What is the best place to mount the relay with battery in the stock location? The pump will be mounted behind the gas tank and my battery is in the stock location on my 66 (so front of car, passenger side. I know capt. obvious for this forum :smile2:). I am thinking it is better to keep the relay closer to the battery but not sure. My thinking is that the longer runs should be the wires to the switch (inside car) and to the pump (somewhere on the firewall might split the difference). Pic shows my current my plan. Also, wiring diagrams from the two parts below. Respectfully, I am not looking for reasons why I should stay with mechanical so please don't waste either one of our time. Not trying to be a jerk but the decision is made and looking for some help on these questions.

Also, I bought this wiring kit from Summit (part # SUM-890009) and they have a 30 amp circuit breaker included but I am thinking an inline 15 amp fuse would be better. What do you guys think? That is what Aeromotive recommends (see below).

Wiring diagram from Summit with kit
https://static.summitracing.com/global/images/instructions/sum-890009.pdf

Wiring diagram from Aeromotive pump
https://static.summitracing.com/global/images/instructions/aei-11203.pdf
 

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I’ve always thought like you, that it’s best to have the relay close to the battery. But maybe others here have good reasons to do otherwise?

Additionally, have you considered wiring in an impact switch so fuel pump power will be disconnected in the event of a collision? I’ve done a few of these and always just sourced the impact switch from a salvage yard.
 

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Have you thought about powering up your relay from an oil sending switch? NO oil press.... Ign,,Pumps,,fuel it all shuts down.
Along with a pushbutton bypass for starting. Many ways to do this pick a good one!
Bob
 

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Discussion Starter · #5 ·
So, still wondering what other guys did wiring their electric pump when battery is in stock location? Any insights appreciated.
 

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1970 Chevelle, MJ 467, 600hp/600tq, Moser 12 bolt M22Z muncie
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You want the hot lead (with inline fuse) feeding the relay, and the relay itself, as close to the battery as possible, reason being the hot lead to the relay terminal is always hot. The shorter this lead is, the bigger safety margin you have.

Think of it this way, if you have the relay at mid point or in the trunk, where will the fuse for the hot lead be?
 

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This is how i do it.In tank fuel pump,pumps should push not pull.In line filter.I use a painless fuel pump relay from keyed 12 volts ,to an oil pressure switch fuel control,mr gasket i believe.in line 7.5 amp fuse.regulator at engine and all 8an lines for street. Like previously stated engine looses oil pressure pump shuts off.Ive wired in inerta switches but changed to oil control switches.Nothing worst than a pump spraying fuel on you upside down if you have an accident.
 

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Discussion Starter · #8 ·
You want the hot lead (with inline fuse) feeding the relay, and the relay itself, as close to the battery as possible, reason being the hot lead to the relay terminal is always hot. The shorter this lead is, the bigger safety margin you have.

Think of it this way, if you have the relay at mid point or in the trunk, where will the fuse for the hot lead be?

Thanks, I followed this advice. I will take a pic of where I installed the fuse and relay. I am not that happy about the location but it seems to work and follows this guidance.
 

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Discussion Starter · #9 ·
This is how i do it.In tank fuel pump,pumps should push not pull.In line filter.I use a painless fuel pump relay from keyed 12 volts ,to an oil pressure switch fuel control,mr gasket i believe.in line 7.5 amp fuse.regulator at engine and all 8an lines for street. Like previously stated engine looses oil pressure pump shuts off.Ive wired in inerta switches but changed to oil control switches.Nothing worst than a pump spraying fuel on you upside down if you have an accident.
Where did you mount the relay? I will be looking into the oil pressure switch, that seems like a much safer bet than the simple toggle switch I installed.
 

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Discussion Starter · #10 ·
One other thing for my education and is probably a dumb question.

How does the 30 amp circuit breaker differ from the inline fuse (which is what I went with since Aero recommended that set up)? How does the circuit breaker protect from fire, etc? I understand how the inline fuse works....Fuse blows and the hot lead connection is broken, circuit stopped. The circuit breaker I got with the kit mentioned in OP doesn't have anything to reset or a fuse connecting the two posts on the circuit breaker. Is there some internal mechanism in this thing? If so, then how do you reset?
 

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1970 Chevelle, MJ 467, 600hp/600tq, Moser 12 bolt M22Z muncie
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One other thing for my education and is probably a dumb question.

How does the 30 amp circuit breaker differ from the inline fuse (which is what I went with since Aero recommended that set up)? How does the circuit breaker protect from fire, etc? I understand how the inline fuse works....Fuse blows and the hot lead connection is broken, circuit stopped. The circuit breaker I got with the kit mentioned in OP doesn't have anything to reset or a fuse connecting the two posts on the circuit breaker. Is there some internal mechanism in this thing? If so, then how do you reset?
Can you post a pic of the breaker?
It’s probably one of two types, manual reset or auto reset. Manual reset breaker types will have a reset button on the exterior casing, auto reset breakers will automatically reset the protected circuit after a cool down period. Hopefully yours is a manual reset type.
 

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I installed mine using a VW/Audi relay (used on dune buggies) that shuts down the pump without a tach signal from distributor. When you turn the key to ON position it turns on the pump for 3-4 seconds, enough to fill the carb bowls and than it turns the pump off until the engine is started.
 

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One other thing for my education and is probably a dumb question.

How does the 30 amp circuit breaker differ from the inline fuse (which is what I went with since Aero recommended that set up)? How does the circuit breaker protect from fire, etc? I understand how the inline fuse works....Fuse blows and the hot lead connection is broken, circuit stopped. The circuit breaker I got with the kit mentioned in OP doesn't have anything to reset or a fuse connecting the two posts on the circuit breaker. Is there some internal mechanism in this thing? If so, then how do you reset?
We all have to learn things and it's great you ask questions to want to know more.

Basically do a search and see what style breaker you might have:

https://www.google.com/search?q=aut...uoPdAhUBvVMKHZY5B78Q_AUICygC&biw=1366&bih=656

A 30 amp fuse and a 30 amp breaker basically do the same thing in that if the current (amperage) exceeds this 30A of current, then the flow of power is stopped by opening up the connection of one end of the fuse to the other or from one end of the breaker to the other.

Years ago there were only fuses out there with a short section of fuse material between one end of the fuse and the other. When too much current was passed through this material the material would melt apart thus stopping the flow of power from one end of the fuse to the other. A fuse is a one shot protection device in that when too much current passes through it and the fuse material melts apart there is no way to easily replace this melted section so the fuse get's thrown away and a new one of the same size and type is used to replace the blown one.

At some point someone figured out how to make a device called a circuit breaker and a circuit breaker does the same thing as a fuse in that if too much current passes through it, the flow of power get's stopped. Due to the design of a breaker, and there are two types out there, is when a breaker does open up inside the flow of power is stopped and then once the reason for it opening up (excessive current/amperage flow) is corrected, the circuit breaker can be used once again and not have to be replaced.

The circuit breaker was also designed in two configurations. In both ways if an overload occurred, the breaker stopped the flow of power and then the one design would allow power to be automatically restored once the reason for the overload was corrected and brought down to below the breakers rating while the other type would still open up and stop the flow of power but instead of automatically reconnecting once the issue was resolved, one has to manually reset the breaker for it to pass power once again.

You might want to do some google searches on how a circuit breaker operates and it might give you some more insight.

Also keep in mind that a 30A fuse or a 30A breaker should pass this current all day long, 24/7 but they will not open up or stop the flow of power if asked to pass 31A. they will or should do that but you will find out that fuses and circuit breakers have different operating characteristics in that one type may be rated at 30A and it can pass 40A for 2 minutes before it blows or opens up while another type still rated at 30A might pass 40A for 10 minutes before it blows or opens up.

My opinion is to either use a fuse or a manually re-settable breaker. If they stop the flow of power, then this is telling you one needs to find the issue and correct it. Below is in a vehicle I had to work on and it had an automatically re-settable breaker in the fuse block and it caused a BUNCH of damage.





In the above picture to the right and below that melted spot, those small rectangular boxes are automatic reset breakers.

Jim
 
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