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

Remember, each fuse or relay slot is limited to 30A so a single 75A trailer circuit should be separate from the Bussman and have a dedicated fuse or breaker. I’d recommend a breaker so you can easily de-energize the circuit when not towing. Any individual circuits(lights, trailer brakes, etc) that don’t exceed the 30A per circuit limit can be run through the Bussman so if it’s just the total that exceeds the limit then you’re gtg. Also, beyond the 5 relays housed in the Bussman you can use any of the other 5 fuse slots to supply power to 5 more remote relays so it’s possible to have the Bussman supply power to up to 10 relays but only 5 of them would be built in. Just remember, the 80A limit applies to what you can have on at any given time. Just as your house electrical panel carries more in breakers than it can safely supply so can the Bussman(add up all those 20A and 15A breakers and you’ll see what I mean).

 

Did you get this powdercoated? Have it coated yourself? Or rattle can?

 

I will be buying a large number of parts for my cooper busman to build two of them for my Tacoma and a 4Runner.

If anybody is interested I’ll piggyback my order and buy them what they need to make this. I’ll probably be ordering next month!
All I ask is a fair extra cost, that’s still cheaper than going the route of buying it all from the websites mentioned in guide. I totaled it and it came out to about: 300 due to outrageous minimum parts purchases. So please feel free to DM me.

 

I also have some parts lying around from the minimum order number I had to get when I built mine. I can let you know what I have and maybe we can work something out.

 

That would be awesome. I need enough for two of the 15303-2-2-4 .

 

DelCity has all the stuff you need(Bussman, relays, terminals, connectors, breakers, fuses, even wire at good prices) except the Tacoma specific mounting plate along with lower minimums(low enough you don’t have extras if you don’t want them) and if you go over $99 shipping is free(not hard with one build and almost unavoidable doing two). Under $99 and it’s better to buy elsewhere but I’ve yet to find a place that can beat them if you do spend that much.

 

Rattlecan...

Gave it a good sanding ro rough it a bit and tk remove the oxide. Then an acetone wipe, etching primer and then filler primer , sanding with some.fine sandpaper repeat filler primer then a several.coats of satin black.

Once I get the bigger powder coat oven done, I might pull it off and beadblast and powdercoat it.

 

So I’m ready for switches. Has anyone found some mini-switches of good quality that you could fit 4 into the change pocket area on the left side? I know they make 3 please panels for oem style or Carling type rockers but I want to fit 4 in there. S-tech sells some but I was wondering if there are others and also how people are doing their switch layout if not doing the OP’s method. I have crawl control there and no sunglasses pocket. I like MeSo’s panels but they have not come up for sale.

 

You could use some "double" switches. They are available from a number of sources. You just need to source a face plate for the "tall" Toyota switches like this one.

https://www.extremeterrain.com/cali...VBwCGCh0cLQAxEAYYAiABEgJyuPD_BwE&gclsrc=aw.ds

 

I notice a lot of people using the blue sea fuse box or the switch pros setup. Those do not have relays. Are they not worried about having so much power going straight to the switches?

 

Doesn’t the switch pros use solid state instead of relays? FET’s can handle way more than 30 or 40A. The “switches” on the switch pro only handle signal level current.

 

CustomConnectorKits has 10% off for November, use TURKEY10

 

Has anybody installed switches to the right side of the left oem dash switches, behind the oem driving light switch/brights for driving, location?
I plan on installing 3 ch4x4.com swtiches there with their mounting plate and was just wondering if there's enough room behind that location or if it's possible to make enough room behind it.

 

Yes, there’s room. Uh, wait, you mean to the right of the upper row of switches? I just checked and there’s frame and stuff behind there. Maybe enough room for one or at most two but the surface is curved and the ch4x4 panels are flat. You’d be better off with an IGGY panel in the center cubby or around the cup holders

 

I also added one to the armrest panel.

 

pics??

 

Not of that one but my sig link shows how I made panels that go in the center cubby and also replaced the 4-slot/2 power ports with 7 small switch slots. I basically added more abs to the back side of the armrest panel and made a router jig to cut a stepped hole for the rocker switch to snap into. It made sense to me to put my sliding window control with the other window controls.

 

I have to say I was completely impressed by this post. Most informative - and exactly what I was looking for. Loved it!

 

What’s the difference between a 5 pin, and a 6 pin relay?
Also which fuse should I tap for power so I can use a relay, on it’s own, almost like a switch to turn on or off something.
Or can I do this with a 6 pin relay? And would I be better off with a 6 pin relay? Also what’s the max amps I can send to one of these posts if I was to steal ignition power to know it’s on for example a under-seat lighting kit.

I also wanted to do this with switched power and a switch in the cab as separate, both on to activate just like the previous question, for the acc portion to hard wire a dash camera.

 

Not much, both are used to switch between two circuits but the 6-pin has two common terminals along with the normally open and normally closed pins plus the two coil pins. If all you want to do is turn something on you can use a 4-pin relay. A 5-pin relay can switch between two possible “on” choices. Connecting two 5-pin relays together you can make a reversing switch for motor control (windows etc.) or use a dpdt switch if it has sufficient current rating.