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

Grateful for this thread!! Thank you!! I'm trying to follow the OP's build post to a T.

EDIT:
Re-reading the thread, I see I have tanged Metri-pack 280 connectors and need tang-less for the RMTR. Gonna order them now! Thanks!

Question/problem for the collective wisdom:

I'm having a hard time getting the Metri-pack connectors to stay inserted into the RTMR. I know I have the correct orientation since there's only one way for them to go. I first thought it was my crimping method on several different gauge wires so I tried inserting a blank/new Metri-pack connector into several of the empty RTMR slots and even the blank connector doesn't get grabbed by the RTMR. I've even tried bending the "tang" of the Metri-pack connector a bit for what I'd think was a more positive lock but am getting nowhere.

Please help!

 

If everything you say is accurate, the orientation is correct, you are not accidentally using the tangless terminals, and you have a genuine RTMR, it should work fine. So first, check to make sure you have the right series of terminals, (Metri-pack 280 IIRC), after that, check to see if you can confirm the RTMR has the plastic "fins" for the tang to latch against. Aside from hat, I don't have any other guesses, can you grab some pictures of your terminals and rtmr ports?

 

Thanks for posting!

I was actually just re-reading the thread and discovered that, to populate the RTMR, you need tangless 280 metri-pack connectors. I was using the tanged ones. I'll get the proper ones and should be good to go. Thanks again for posting!

 

It seems the common sites like Paranoid Fabrications stopped selling the aluminum 3gen RTMR mount plates. Anybody know of a source that still sells a bare aluminum mount?

 

Not that hard to make one from alu bakeware.

 

If anybody has a usable CAD file for the tray please let me know.

Might end up using this fuse array off the batt and a 5-pack of Nilight waterproof relays to save time.

 

I’ve got flat blank geometry that I drew up to make a stainless mount. If anyone wants to use it as is or modify it let me know and I’ll email you a dxf.

 

Idk about 3rd Gens but...ok yeah, it's a kinda an elbow turner getting the two bolts to catch into the pre-threaded holes on the side of the engine bay (half sarcastic). The first one is easy, especially the way I designed it with the slots, and multiple prototypes inching things around mm's at a time for optimal hand/wrench clearance - don't forget the bolts (small ones for mounting) and big ones (+ and - studs) sticking out the bottom in addition to your actual wiring...and the (acute) angle of the wall you're bolting to. I bent mine ~2-3º past 90º (PS don't remember the exact angle....I'd have to look up my notes, if you actually need this info pm me). (also idk if mines unique dont @ me). The second bolt (usually front/bow side) can be a challenge. Sometimes you get it in right away. I found a little Icon 1/4" Flex Head wrench at HF that helps a ton.

If I redo it, and I may bc the dealer ripped it out while doing my free frame swap, then didn't rewire everything ....I'll probably add "keys" to the slots kinda like what you find on the back of power strips. Then you can just slip it on, then worry about tightening.

Fitting and routing the wiring was not an issue at all for my 2nd gen...if anything I ended up with less clutter. Each run is wrapped in TechFlex with a different tracer color. (srsly...how did the dealer not know how to...ugh nvm). And the fuse cover on my EATON 15305-2 pops on and off fine. I designed in extra plate space for possible add-ons later like a battery shutoff or voltmeter or something, but easily could have just not and then you'd have an even better time bolting the plate on.

The concept of this RTMR endeavor is you install it once, with future upgrades already baked in - the plugs are all right there (make some longer or shorter to suit your wants/needs, and run all possible switches during initial install even if you don't have a need yet. Leave an extra 10-12" wrapped up under your headliner). Label everything and heat up some WireCare Ultra Clear ShrinkFlex to protect the labels. Write down your labeled schematic, and you should have no issue adding a light bar, or a winch, or f*uc it add hydraulics and bAAAAAAaaAAAAsss. W/e the kids are into in 2025. Whatever you desire down the road, planned or not. If you have to go through a whole ordeal to add an accessory later, you did something super wrong.


[1] Ratchet image attatched - the plain 1/4" drive variant, not the one with the comfort handle. Also I'm sure theres something even better, I just impulse bought that one day. Wera has some good options)

[2] Crude cardboard....refined paper model...clear acrylic model...finally ss waterjet and bent. Drove around with the acrylic installed and functional for a couple weeks to identify any tweaks before making the final stainless plate.

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Attention Friends

Haven't been on in a while but saw a few posts from people looking for plates, certain fabs stopped making them, etc. I'll do y'all a solid if a few people jump on board.

Poked around and it looks like the fab shops are selling .125" Al plates for like $150-$200? I can do it for half, maybe less. Say, $75 for 3mm aluminum or $100 for 3mm stainless steel (kinda overkill) or $80 for 1.5mm stainless. I can pump out 2nd gen plates now, and 3rd gens if someone sends over a confirmed good fitting flat file. I wouldn't do plain steel personally but prob $90 for 3mm mild.

$220 for 3mm fire rated carbon fiber or 3mm chromoly if you're feeling spicy.

Numbers off the top of the head at the lowest I cost I could imagine it covering time and cost, so don't hold me to them atm. Prob less tbh. Lmk if there's legit interest.

 

You can easily add a winch or compressor to your system (for say, in-cab winch switching) with the proper relays/solenoids from Eaton or Blue Sea. I have winch power toggle and In/Out in cab on 5v switches.

 

Just to be clear, the individual circuits for either Bussman or Blue Seas fuse panels aren’t rated for the full current of compressors or winches. Yes, you can power switches that then actuate high power relays or solenoids fed from dedicated high amp fuses or breakers through them but ~30A per circuit is it for the panels themselves.