Another 12V Aux set-up, help please. (1 Viewer)

[divemedic]

So I need to get my electrical situation straight AND dummy proof. I've posted here prior for a radio install about a year ago. It didn't go so well. The original design was overly complicated and I couldn't get it to work properly for me. After 2 weeks of trouble shooting I said screw it. I ended up running the radio off the first battery. Memory was directly wired and ACC/P-control was controlled with a switch. This worked fine while I was living in Okinawa (its always hot). However, after moving to Ohio, the cold weather (along with my wife forgetting to turn off the radio) has caused issues. I've done more digging but I'm still lost in the sauce.

Engine: 1PZ
Goals:
- Isolated 12V system with 3rd 12V battery and 12-blade fuse block
- Only power Redarc BCDC1220 to charge 3rd battery when truck is running (may consider solar trickle charge in the future)
- 12V constant power for head unit's memory (Kenwood calls it "batt") and refrigerator
- 12V switched power for the fuse block

Current/Future electrical accessories.
- 24V aux driving lights
- 24V winch
- 12V headunit with 4-channel amp
- 12V USB port x4
- 12V refrigerator

Issues:
Aside from being stupid on this stuff, I really have a heard time understanding how relays work and how to wire them correctly. I really want to use them because I don't want to deal with my wife draining the battery because she forgot to turn of the radio. I think I've figured out how to run and charge the Redarc and the 12V battery. However, I don't know how to create a switched 12V power supply on the fuse block that is controlled with the truck's ignition power. I am okay with putting a manual switch after the load fuse between the 3rd battery and the fuse block, but would rather control it with the turn of my key.

Here is a diagram of what I'm thinking would work, but it doesn't have switched power for the fuse block.

The relay is a Hella 30A 24V unit

Note 1: bridged Constant power and power control on the Redarc

Note 2: disregard

Note 3: How do I add switched power to the fuse block?

 

[ozcrusier]

That looks great to me but Solar can keep the 12 volt battery charging when parked for a few days running the fridge etc.
Ideally you need the Redarc while driving + Solar while the suns out and a small 15 or 20 amp multi stage battery charger to run from a generator when you get a week or two of bad weather.
It never ends

 

[divemedic]

I agree, for now I just want to be able to run a few USB ports and my radio. @sbechtold and I have been talking via pm. He's been a huge help. I'm going to add to the above diagram with notes and post it later today. I'll also link my build thread so the finished results/fine tuning can be seen at a later time if anyone finds this here and wants help.

 

[divemedic]

Updated diagram. I added in quite a few things. @sbechtold thank you letting me know I could use a 24v switch to activate the relays.

I've got most of the supplies on hand I'll need to figure out where I'm going to put it in the truck. Hopefully I'll have it bench tested and installed this spring.

 

[sbechtold]

You might consider hanging the BU Camera relay and the Dimmer relays off the Blue Sea 5026 fuse block with the rest of the stereo connections. No need to have them on constant 12v power on the Blue Sea 5045 that is hanging off the 12v battery.

Also... I assume you are using the Blue Sea 5045 between the 24v battery and the Redarc purely as a connection point (with future flexibility for other 24v systems) .vs just soldiering and shrink tubing the wires?

 

[divemedic]

Makes more sense. I think that was just a "typo"

 

[jblueridge]

I run my 12V stuff from a Blue Sea fuse block that is powered by a 24-12V converter. I put a trolling motor circuit breaker on the 24V line between battery and voltage converter. This line also runs though a relay such that the ignition triggers the 24V power.
I spent some time with a label maker and volt meter testing all kinds of wires in the dash.
I was able to find constant power (from the OEM claock I think) and lines to dash lights that I used as relay triggers for 12V gauge lights and radio faceplate lights. Often, I have a 24V relay that controls 12V power.

 

[divemedic]

That's clean. I like it!

 

[jblueridge]

I need to make sme wiring diagrams for all the 12V stuff.
I bought a wirng harness from a junk yard just to get many colors of wire insulation... Easier to trace stuff later.
Last bit was the power to my e-locker. Locker itself not installed yet.

 

[jblueridge]

I like to buy from Digikey. Their Search engine is very useful just to find out what is out there.

DigiKey Electronics - Electronic Components Distributor
https://www.panasonic-electric-works.com/pew/eu/downloads/ds_61202_en_cb.pdf


You should think about using the appropriate socket bases for relays. Example below.
http://www.digikey.com/product-detail/en/te-connectivity-potter-brumfield-relays/1-1904045-2/PB1317-ND/331813
I found dual wall shrink tubing when I was making new battery cables. Amazing stuff.
Dual Wall Heat Shrink Tubing - Black - 4-ft Sticks
Heat Shrink Tubing | DigiKey

Your diagram threw me for a second... I am used to seeing pins 85 & 86 on opposite sides.