Wiring in another fusebox Options

[match220]

SOOO..with the aftermarket computer that I put in my car, I needed a separate fuse box to power some things. Bought a fuse and relay box off of eBay that is from an 05 Mercedes, opened it up and traced out all of the internal wiring of it. Since I went to all of the trouble to map out the internal wiring and draw a diagram, I figured I would share the info in case someone else wants to do the same thing. The fusebox is small enough to mount in most places, has three 60 amp relays, two relays each have one fuse on them, the last relay powers three fuses. Below is a picture of it, inside and out, as well as the diagram for it. It is from a Mercedes w220 I believe and also fits the w215, w220, cl500, s55, s500, cl500, and s430. Maybe a mod can pin this just in case someone actually wants to do it. Whoever decides to do this MUST follow the wire diagram though, it has all of the answers on it. As I said, these are 60 amp relays, so it can handle a huge fuel pump, big amp, big inverter, or most anything else. I got mine on ebay for $15 with the bosch-style relays ($20 a piece if you buy them in the store). You can probably get this fusebox from a local junkyard, or dig around on ebay to find one using the mercedes models I listed above.

The simple thing about wiring it...all you will need is two power wires from the battery, two positive switched signals (from an actual switch or from the ignition), two regular ground wires, one ground switched signal (from an actual switch that connects the circuit to ground), and then you will have five wires to power whatever you want. Everything is labeled in the diagram, the top half is complex, the bottom half is easy.

I decided to get a little creative and wire in another relay directly to the ground switched signal so I could turn it into a positive switched signal and use it with the other relays.

this is what it looks like. It's upside down, so the fuses are numbered (left to right) 91, 90, 89, 88, and 87. The 91 fuse (10amp) is connected to the relay it is in front of (marked "X" on the fusebox). Fuse number 90 (10 amp) is on the center relay (marked "W" on the fusebox). Both of these relays require a positive switched signal to trip the relay on. Fuses 87, 88, and 89 are powered by the remaining relay (marked "V" on the fusebox) and it requires a ground switched signal.


the insides


The wire schematic. Top half shows the inside wiring for anyone who wants to get creative with it and try something else, the bottom half shows the easy break-down on the wiring.


and the finished product..I cut out some plastic for it to sit in between my battery and fusebox


This post has been edited by match220: Apr 10, 2013 - 4:42 PM