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Adding Relay/Fuse Box for Accessory Circuits

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Wondering how people have added supplemental relay/fuse boxes to their car to power additional circuits such as diff cooler, trans cooler, gauges, etc?

In the past I've added single circuits as needed but thinking it would be better and cleaner to do so via a fused relay box such as the attached examples? I may only need one or two circuits now, but was thinking it would be nice to add such a box now and then be able to easily add new circuits without creating a rats nest of wires and splices.

I like the painless as the wires are already terminated in the box, but the amazon one gives more flexibility.

What have you done?


TMO Addict?
Exp. Type
Exp. Level
10-20 Years
The Painless one has to go some where that is always clean and dry. The Amazon one can take more abuse but I always prefer keeping electrical components in a clean and dry location if possible. The Amazon one is nice as you can use the wire size you need for the circuits and also you get to choose the quality level of wires.

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