DIY - Build and install a Bussmann RTMR Fuse/Relay Block

@tacozord

Any thoughts about using tinned marine wire???

 

I don't see any problems using tinned marine wire, yet it's not really necessary. If that's all you can find, however, then go for it.

Also, you may find this interesting: https://www.practical-sailor.com/systems-propulsion/electrical/tinned-wire-myth-busted

 

For any Canadians shopping around for this stuff for (future reference), I found:
- Bus bars
https://ca.binnacle.com/Electrical-Bus-Bars-Junction-&-Terminal-Blocks/c58_185/index.html
- Circuit breakers (including this one with a seal/bezel)
https://ca.binnacle.com/Electrical-...ircuit-Breakers-Panel-Mount/product_info.html
https://ca.binnacle.com/Electrical-...el-Mount-Adapter-285-series/product_info.html
Binnacle ships out of Nova Scotia and has free shipping Canada-wide.

- GXL & TXL Wire (site in USD, $29USD shipping, but out of Ontario and no duty)
https://www.racetronix.biz/c/wiring-components-aids/wire/c673

Literally everything else from Mouser. Its all there. Everything.
I'm poor now.

 

Well, here we go!

 

Already I've made a slight error, maybe. I followed the directions a bit too closely and wired my black wire to the ground bus of the Bussmann, not remembering that I won't need that for the switch ground. I suppose it won't hurt to leave it, but I've limited myself maybe.

 

@tacozord, I had a question about part 2 of making the switch harness.

I've cut my wires at 90", it has the male six part connector on it, and a 22" length of braided sleeve. Then it connects with the other cables, joins into an 85" long braided sleeve. Should that really be 55"? I seem to have about 30" of braided sleeve longer than the wiring.

 

Leave it in the 6-way connector but pull it out from under the fuse jumpers. You can use it to trigger another relay. This is especially nice if you have something that could draw more than the 30A per circuit Bussman max.

 

Putting in these jumper wires is an absolute pain in the ass.

 

I retract this, and substitute the following:

Getting these terminals in the Bussmann is an absolute pain in the ass.

 

They go in pretty easily if they’re aligned correctly. You shouldn’t have to force it. The tricky part is crimping them so they can line up without having to twist the wire to get the other end in. Getting them out again out is why I solder though.

 

Some of them were an absolute pain, like a degree off. Not sure I got them all clicked in, but there was no getting that last bit of travel.

 

The box is done, minus one fuse only lead (ran out of terminals and black 10ga). Can always add later if I don’t get replacements before final install. Tomorrow maybe run switch wiring.

 

Cleeaannnn

 

Nice!
I'm jelly; stoked for my stuff to come in so I can get on it as well.
I was debating on buying that Powertrays mount as well, or doing one up in CAD to 3D print, or another style.... not sure yet.

 

I think ideally it would be hinged. It’s difficult to plug the connectors trying to reach in/around/under/blind.

 

That had crossed my mind; I was leaning more towards measuring and constructing longer tails that stick out of the RTMR and make a header mount that is easier to reach and tuck your harnesses to their respective destinations in OEM fashion. I figure once I get all my components in I could start imagineering potential layouts, taking photos, measurements, and doing up some CAD sketches. 3D printing would be cool - a close friend of mine picked up this 3D printer, I'm sure what ever mount design gets drummed up can be a multi piece if required since it may not fit on the plate in one go... Buuuut most likely make the mount out of metal when considering rigidity and durability though (thinking of thermal cycles for -40ºc to max engine bay temp in summer).

 

I would LOVE a hinged mount. Getting around the fuse box is a pain.

 

I wanted to thank @tacozord again for a great how to. It's given me some knowledge and thoughts beyond the initial build. I have thoughts of making a five relay panel otherwise to fully utilize the Bussmann.

I also had a question about the capacity of an add-a-fuse: how many switches could I run off of one, to make things cleaner? Five, sure. Ten? Fifteen? The add-a-fuse comes with a 16ga wire. If I need to use two, I will. Just mapping out wiring runs and needs.

 

10A worth, good for maybe a hundred relays.

 

So I could run any internal switches I wanted to as long as they are just suppling power to a relay. Awesome.