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

Thanks for both of your responses.

Got it. So using a terminal block would be used if you didn't want to use the plug style connectors and wanted another easy way to unhook the positive end of your accessories. I'm planning on just using your basic waterproof heat shrink connectors.

 

Exactly!

 

Like 75 to piece them out i believe. Im selling my fully built bussman relay box wired up for 100$ Shipped US went to switch pro style controller but loved my relay

 

Would u sell just the metal base with no electrics on it?

 

Are you talking about the bracket? If so, then Yotamac sells them. I gave the link in the parts section of the tutorial. Here it is again!
https://www.tacomaworld.com/threads...ete-kits-and-blue-sea-mounting-plates.294195/

 

Thank you

 

It’s a little difficult to tell from the photos but the wires for the accesories go in the bottom cavities correct?(red)

 

If you're copying tacozord that's the switch wire hole for the relay. The top hole(yellow)goes to accessory. Jumpers from fuses go to solo holes far right. Blank is where the relay plugs into the buss for grounding the switch side of the relay.

 

So the red hole goes to the switch and the yellow one goes to the accessory?

 

Yes.
On a 4-pin relay the connections for the switch side and accessory side run diagonally so when you turn on your switch it energizes the red pin passing through the relay to the grounded bussbar via the hidden pin. Accesory power then can pass through the fuse, across a jumper to the far right bottom pin, then through the relay diagonally to the upper left yellow pin and out to the accessory. It's all covered in section 4(post #4) by the op. It does seem to take a few reads for it all to soak in so I hope this helps. There are other ways to wire it since relays are not polarity sensitive but the way the op does it works and seems to be tidy with the wires.

 

Sub'd. What a great write up.

 

I was wondering if anyone has any information for a cut out diagram for the RTMR so I can cut the ones I need myself.

 

That information can be found here under the Sales Drawing link. http://www.cooperindustries.com/con...r_distribution_modules/series_15300_rtmr.html

 

Thank you sir!

 

Figured it out

 

The switches are fed by a 12v source usually with an add a fuse from the internal cab fuse panel. They are connected to the 5 wires in your 6x connector and when one is pressed it activates the corresponding relay. Take the output from that relay and connect it to an accessory and then from the accessory to ground(either on the frame or back to a ground buss that's connected to the battery. Repeat 4 more times for the remaining relays. The fuse only wires are for things that are either always hot or switched elsewhere down the line and are grounded after that.

Read the op maybe 4-5 times, it's not that he's not clear, it just takes awhile to absorb it all. Pretty soon though you start thinking "I got this" but read it a few more to be sure.

One of the advantages of building your own is your forced to do the reading and by the time you're ready for install it's a no brainer. By short cutting the assembly you've skipped the part where your brain gets indictrinated. Don't worry, it wont be held against you, just do the reading and ask about anything that's not clear.

 

Almost done with final things and install. If anyone needs spare parts let me know. Ill have some laying around for sure.

 

Does anyone know of a 280 size timer relay that can be used for a defrost circuit? Basically just a relay that has a timer built in to shut off after 10minutes or so.

 

Amazon has them in the Bosche form factor but a search comes up zilch for both iso 280 micro and mini.

 

I know there are some vehicles that use 280 size relays. Here's one for example: https://www.partsgeek.com/gbproduct...rztCh12lAlyEAQYASABEgKEkPD_BwE&ad=47433966132

I just can't tell if that is actually a delay relay.