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

Thanks for the responses. I have read the first page many times. I guess I shouldn't have asked the first question as I knew that you could put them up there but was just wanting to know if the switch backings would fit haha

 

It's a lot to absorb. I'll be doing it eventually after both my brain and wallet have absorbed enough. I've started acquiring bits but want to know more about what I'll be hooking up to it as well. That list is steadily growing but the more I know the better I'll be able to order correct parts. Take your time and reread it cover to cover until you have it down pat. If you're like me there's lots of new concepts and this is one place you really have to get right the first time.

 

Can i use 14 gauge wire for the switches?

 

sure, but overkill if you are just triggering relays.

 

Its because i already have some.

 

This is music to my ears. You exemplify exactly why I wrote this tutorial. Research. Plan. Prepare. Learn. Build. Right on! Looking forward to seeing your install.

 

Using switchbacks would have been nice. But they simply won't fit in the sunglass holder. That's why I built it the way that I did.

 

Thanks, you've laid it all out so well I want to fulfill the promise.

Technically I don't think so unless they simply don't fit. Awg14 is going to make a much thicker bundle going through the firewall and up the A-pillar.
One question I'm trying to resolve is I'm planning on using an MF1050 compressor mounted somewhere aft of the drivers seat forward of the rear wheels(~8-10')and it uses calls for a 30A fuse which seems at the upper limit for the Bussman fuses and relays. Should I instead use a separate 40A fuse/relay with Awg8 or will awg30 w/30A relay be sufficient? The max tank size will be 1.5 gal w/ a 90-120psi switch and it won't be used for long, high volume fills(mostly air bag adjustments).

 

According to the Specifications of this compressor, it's recommending a 30A fuse. Therefore, you should be good with 10AWG wire and a 30A fuse connected to the RTMR.

https://static.summitracing.com/global/images/instructions/qin-mf1050 manual.pdf

Keep in mind that the RTMR is rated for a total of 80A. So it's certainly rated to handle the compressor. You just need to heed caution when running multiple accessories that could potentially breach that 80A threshold. With that in mind, you simply need to use the correct gauge wire and fuse as I indicated above.

Cheers!

 

Thanks, a big part of planning is listing and tracking these various considerations. When I have a more complete idea of what all might be added I can decide whether any fuse/relays need to be outsourced if the total simultaneous current gets too high. I think the high current additions are likely to be short duration usage(compressor, heated seats, etc,) so I would just have to be careful to not hop in and start flipping things on willy nilly. And get an 80A breaker so I can say "oops", instead "crap!". Since joining I've spent many hours reading just a small portion of the amazing mods here trying to pick out what things I'd like to add. This popped up as one of the foundation mods. Some others are neither mechanical nor electrical in nature so they only wait in the wallet que. then again, I haven't nearly finished reading so who knows what I'll find.

 

And thanks for the mf 1050 link, just what I needed since little of that is on the outside of the box(checked one out at pep boys).

 

Nice price for 100' of 10 ga Txl on flea bay http://www.ebay.com/itm/Copperfield...range-100ft-/162543019063?hash=item25d851a437

 

The most difficult thing about this is the shopping.

 

Ordered the rtmr so I can work on the mounting plate while I figure out how much other stuff to get.

 

So, has anyone added up the total cost of starting from nothing?

 

Total cost is a moving target and depends on how you buy the parts to assemble it and the add ons like connectors, welding cable, fuses or circuit breakers, mounting panel, external buss bars, accessory connectors, switches, interior mounting panels... How much "it" costs depends mostly on what "it" is. Some places like Delcity have low or no minimums but the pieces cost a bit more. Still cheaper if you're building only one than buying the minimums from Waytek but if you're building several than it goes the other way. Plus there are some tools to buy which add up. The actual rtmr and 5 relays is ~ $50 shipped from Waytek if you order nothing else from them and put the rest of your kit together a la carte from several sources. Given the high degree of customization inherent in each build I don't see how a GB could work even if some poor slob were willing to bag up each of the many groups of parts and reship. The only options really workable are buy one that is maybe what you want or build one that is what you think you want and order heavy on connector parts. When I finally decide on my order I'll certainly post the total but it probably won't be the same as someone else's.

 

^^ this. I ended up going with the 40fuse/10 relay setup and bought most of the connectors, relays, and cables up front. Since I was buying so much extra, I probably spent closer to $400-500 in total but I have a bin full of parts to wire up future accessories and I rewired most of my existing accessories. Depending on what setup you go with, it could be cheaper, same, or more expensive than what I spent on my setup

 

I spent roughly $500 for parts and tools. But I got enough stuff for two RTMRs and one set of upgraded battery terminals/cables. Add another set of battery terminals plus an 80 or 100 amp breaker and I can complete the second setup.

If price is your main concern, just buy one already made. Also worth noting, I did NOT buy the molex crimper. I am a believer that you should use the right tools for the job but I wasn't about to buy a $50 tool I was gonna use once. I managed without it but having that tool would have been much faster/smoother.

 

Price is always a concern lol.
I like the idea of building it myself just because I like to tinker.
If I could buy one with the same quality I might consider that but I do not know where to buy?
Thanks

 

Check the op but I think there are one or two places listed there where you can buy the rtmr alone already assembled. You would still need to put together a kit for the rest of your connections though.