Wiring schematic question

[Boiler Ben]

I’m looking for advice on marking up the FFR electrical schematic to include everything I’m putting on. I’ve been studying the schematic and think I get most of it but am having trouble understanding the power connections. I have a Ford FE engine with Holley Sniper EFI and Hyperspark ignition. Both the EFI and ignition box say to wire direct to the battery. I have a 1 wire alternator whose instructions say to wire to the fuse box and directly to the battery through a 200A fuse (it’s a 140A alternator, probably overkill). Planning for the battery in the back and using the 4 pole battery disconnect switch.

[weendoggy]

Holley is VERY specific on wiring to the battery. So, wire the Sniper or any of their systems, direct to the battery, positive and negative, even the CD box.

You can run battery to fuse to disconnect, then to starter, then starter to alternator. From alternator again to fuse panel.

A lot depends on what/how you intend to run your system. Everybody is different.

[Boiler Ben]

If I run the battery through the fuse and then to the disconnect, could I connect the Holley EFI and CD box to the switched side of the disconnect so that all power is cut off when disconnecting?

[rich grsc]

No, how is that a direct connection to the battery?

[Boiler Ben]

Ok, so the disconnect switch seems pretty pointless then. Is there a reason to use it?

[rich grsc]

The disconnect switch has nothing to do with connecting EFI and ignition box directly to the battery. They aren't related, you can still use the switch if you want. The EFI and ignition box need clean power when in use

[Boiler Ben]

My understanding was that the purpose of the disconnect switch is to remove battery power from everything. If the EFI is directly connected to the battery, the switch position doesn’t affect it. It will always have power regardless of switch position. Just trying to understand here, is the purpose of the disconnect for safety, for theft deterrence, something else?

[rich grsc]

Not how it works, the EFI and ignition box do not have power all the time, they only get power from the battery when they get a signal from the ignition turning them on. They MUST have "clean" power

[Boiler Ben]

Ok, here’s another one. If you use a battery tender to keep the battery charged during the winter, does it matter if the battery is still connected? Or would it be better to disconnect using the switch in that scenario?

[weendoggy]

Ok, here’s another one. If you use a battery tender to keep the battery charged during the winter, does it matter if the battery is still connected? Or would it be better to disconnect using the switch in that scenario?

No, I use one all the time, smallest one they have and have a quick connect direct to the battery. The tender is just keeping the battery ready. I use a master switch, but all it does is power the system.

Rich is correct on Holley connections. So many argue the battery connection portion and it's pointless to deal with them. If they don't want to change, I tell them to find someone else to help. Holley has a fuse battery lead so don't worry.