Need help wiring up an aux fuse box. It will be used to power 4-5 switches in my vehicle for various applications. All the switches will be run off relays between fuse box and switch. Now here is the question. I want/need to have positive control over the power that these switches are getting. Which means I either need them all to be powered from a switched 12v source (re: somehow power aux fuse box with a switched 12v power source) or run a switch between fuse box and continious 12v source, probably the battery, so I can cut power to it and know none of the switches will have power when I turn the vehicle off. Any suggestions?

If I run the power from the battery, which seems like the only safe option, what guage wire would you recommend, and should I run an inline fuse? If so, what size? Thanks for the help.

 

If all your switches are triggering relays then you wont need a real big ign or power line. Just make shure the power side of the relays have heavy gauge wire, 12 or 10 should cover any solenoid, heater, or remote valve. I would run 16 or 18 line with a 3-5 amp fuse to your master switch, then 16 or 18 out of that to the rest of your switches. The trigger sides 4 relays all on at the same time will only dray about .09 - .12 amps depending on the brand so you wont need high current switches for the master or triggers.

Let me know if you need more help.

 

Going back over your post it looks like you want to trigger or un trigger relays under your hood in the fuse block. Those relays are almost all negative triggered. To trigger those you need to switch a ground to with with a diode to protect the computer because it put out a high instead of nuetral when it turns off the relay. If you want to make it so the computer wont turn a relay on the you can just break the trigger line with a switch. It is still real low current so you dont need heavy duty switches here eithor.

 

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