DIY Spod/switchpro fuse relay panel

Ever since I posted my DIY fuse relay panel build I’ve been getting a ton of PM’s on what I used, how I wired it, etc.

I figured it’d be easiest to make a new thread explaining exactly how I made it and what I used using my easy 12 step program. Keep in mind, I’m a 19 year old college student doing this for the first time with no wiring experience. I followed a youtube video and it’s actually unbelievably easy to make.

This is the video I followed: https://youtu.be/RY45UHCfeHk

For those who don’t know, this is essentially the same thing as an Spod or switch pro, which can be made at a fraction of the cost. The parts I used were mainly Bluesea and Bussman, however there are many cheaper alternatives that accomplish the same thing. I wanted to use high quality components to reduce the risk of failure.

I built this to replace all of my old wiring harnesses that made an absolute mess in my engine bay and to drastically reduce the positive and negative wires going through my firewall to the switches in the cab.

Before/during removal of the wire harnesses:


Final product (the screws marked with black sharpie are where I chose to connect my positive wires from the accessories. The silver screws go to the switches) :


This fuse relay panel allows for ONE wire to go to each switch total. That’s it. When adding new lights or accessories all you have to do is connect the positive and negative wires of the accessories to the terminals on the fuse block. You can of course customize the panel to accomplish however many lights you would like to add, but I found a 6 switch panel fits best while still allowing room for adding new accessories.

List of parts needed:

For the mount I used a 22ga 12x12 piece of sheet metal from Home Depot for like $10. Bent and shaped using a dremel with a cutoff wheel and a BFH with a 2x4 for the 90* bend.

Relays, they only come in a 5 pack or a 1 pack, so for 6 switches youll need to order one more. Make sure they are waterproof:
5 PACK 40/30 AMP 12 V DC...

$26 irhapsody 5 Pack 40/30 AMP 12V DC Waterproof Relay and Harness - Heavy Duty 12 AWG Tinned Copper Wires, 5-PIN SPDT Automotive Relay

https://www.amazon.com/dp/B074FSZWVT?ref=ppx_pop_mob_ap_share

Fuse block:
Blue Sea Systems 5025 ST Blade...

$30 Blue Sea Systems 5025 ST Blade Fuse Block 6 Circuit with Ground and Cover

https://www.amazon.com/dp/B000THQ0CQ?ref=ppx_pop_mob_ap_share

Circuit breaker:
Bussmann CB185-100 100 Amp Type...

$33 Bussmann CB185-100 100 Amp Type III Circuit Breaker

https://www.amazon.com/dp/B00139FQSS?ref=ppx_pop_mob_ap_share

8 Gauge wire for power leads:
BNTECHGO 8 Gauge Silicone Wire 3...

$12 BNTECHGO 8 Gauge Silicone Wire 3 ft Red and 3 ft Black Flexible 8 AWG Stranded Tinned Copper Wire

https://www.amazon.com/dp/B074P4HSF2?ref=ppx_pop_mob_ap_share

Negative bus terminal for all negative wires for the lights to connect to:
Blue Sea Systems Common 150A...

$22 Blue Sea Systems 2300 150 Amp Common BusBar with 10 screws and a cover

https://www.amazon.com/dp/B0091VHLW4?ref=ppx_pop_mob_ap_share

12 circuit dual terminal bus for 6 switches:
Blue Sea Systems 12 Circuit 30A...

$14 Blue Sea Systems 2512 12 Circuit 30A Terminal Block

https://www.amazon.com/dp/B000K2K6L6?ref=ppx_pop_mob_ap_share

Stupid cheap heat shrink kit:
625pcs Heat Shrink Tubing Kit,...

$9 MILAPEAK 650 PCS Heat Shrink Tubing Kit, UL Approved Heat Shrink Tube Wire Wrap, 2:1 Ratio Electrical Cable Sleeve Assortment with Storage Case for Long Lasting Insulation Protection (8 Sizes, Black)

https://www.amazon.com/dp/B07QM8249H?ref=ppx_pop_mob_ap_share

Switches I used:
Nilight 90017C 3 Gang Aluminum...

$14 Nilight 90017C 3 Gang Aluminum Panel Toggle Dash 5 Pin On/Off Pre-Wired Rocker Switch Holder for Automotive Car Marine Boat, 2 Years Warranty,Blue

https://www.amazon.com/dp/B07TJQ7738?ref=ppx_pop_mob_ap_share

and you’ll need a lot of 12 gauge wire, various sizes of heat shrink, grommets, 8 gauge ring connectors, and fork connectors. Once you have everything follow the video I linked and hook everything up. I used heavy duty double sided 3M tape to stick the relays to the underside of the relay mount.

The switches I used require a POSITIVE switch. I believe the video uses a negative switch, but you can always rewire the switches to a negative load. Here’s the diagram I used.



I will update the post with the dimensions of my DIY panel for those who wish to make their own. It’s much cheaper than paying $100 for a powertray.


Step 1: Build the actual panel for everything to mount to.


Step 2: Begin to layout all your components and grommets for the wires from the relays to pass through. I purchased the grommets from Home depot. Most of the ones I used were 1/2” I believe. You can only fit 6 12 gauge wires through each grommet, hence multiple grommet holes drilled.

*I chose to mount the relays on the bottom for the cleanest possible outcome*



Step 3: Once you have everything in place where you like it, drill all mounting holes for the fuse block, circuit breaker, dual bus terminal, and the ground terminal.

Step 4: Use small hex bolts to secure everything

Step 5: mount the relays with heavy duty double sided tape under the panel

Step 5: Cut off the center wire in each of the relays or pull it out. It will not be used

Step 6: Use either a soldering gun (I used this method) or butt connectors to extend each of the wires of the relays as they will not be long enough. I added 6” to each relay and trimmed them down as needed.

Step 7: Begin to solder or crimp fork connectors onto the ends of the relays to connect to the dual bus terminal and the fuse block. Use the diagram above to determine what to plug into where.

Step 8: Once everything is wired up, crimp ring connectors to the 8 gauge wire and connect the wires to the positive and negative terminals of the battery. I grounded mine on the ground bolt located on the drivers side fender.

Step 9: Mount your switches in your desired location. I already had 3 switches where blanks would normally be, so I purchased 3 more and mounted it in my center console. Excuse the dirty truck.

I used these switches because they come prewired to accept only a positive input from the device. In this case, the positive will come from the dual bus terminal and go to the relay to activate it when the switch is put in the ON position.

Step 10: use a fuse tap to connect the positive leads of the switches to a fuse located under the steering wheel and ground the ground wire somewhere.

Step 11: run wires through the firewall to each switch and connect them to the dual bus terminal. When wiring the dual bus terminal, every other terminal should be a switch with the positive wire going to the accessory in between.

Step 12: Connect your accessories to the ground terminal bus and the positive wire to the dual bus terminal.

Turn the ignition key and test it out to make sure it works! If you have any questions feel free to ask. This is very simple to make and looks very clean. The hardest part of this install is making it look nice. You can follow my layout for the best looking results or do your own take on it!

 

@Beretta4x4 you need to make one for your lights

 

Nah. I don't have the space on that side and the other side will be dedicated to my dual battery and compressor setup.

I did a ghetto version of it last year lol

 

Subbed

 

My setup looks like your before shot. What are the advantages to what you did? Purely aesthetics, or does it improve the function of the lights/make it easier to change things around?

 

Aesthetics mostly, but everything is fuse protected and with only positive wires going through the firewall it’s much less of a hazard having positive and negative wires running through. Overall a much cleaner and safer alternative.

 

I grounded most of my stuff locally at the accessory and only ran a power wire. I did write up the ground on my bussman first block yesterday to run wiring for a QD connection for led lights on my awning

 

Nice write up. All looks super clean, I'm gunna order all my parts soon. Any update on the dimensions you used for the power tray?
Did you just self tap into the inner fender to secure it?

 

I’ll go outside and grab them right now totally forgot. There are 2 bolt holes on the side of the fenderwell. I found 2 bolts in my bolt drawer that fit in there perfectly so I don’t know the threads. Just drilled holes in the side and used ths bolts. On the engine side of the mount, I made a support brace that goes down to give that side support. Ill snap a picture of it. It’s janky but it works and that’s all I really care about.

 

You did a really nice job. I think it’s not necessarily fair to say this is essentially an SPOD or SwitchPro though. There have been a bunch of threads on the debate on the cost of those systems and what you’re paying for etc etc and I’m not here to debate that. Super slick fuse panel set up? Yes. But not essentially a sPOD or SwitchPro system. People who are/may be weighing options should be educated on the vast differences between what you have nicely put together, and a $600+ system like sPOD,SwitchPro or the like offers.

 

True. I’m relating it to an Spod or Switchpro in the way it functions. Yes, they have far more features, but at the end of the day they accomplish the same general thing. I don’t mean to take away from those companies and what they’ve done, I simply want to show everyone an alternative for those who can’t spend $500+ on a switch system. Thank you for the compliments, I tried hard to make it look nice.

 

Here is a crude drawing of the dimensions and a picture of the side brace.

 

Awesome! thanks for the quick reply

 

Going this route you are omitting the negative bus bar?
Looking at other builds I haven't seen anyone running one. I'm assuming they've ground their goodies locally like you said.

 

Pretty much, but I've since grounded my aux fuse panel in order to ground locally near the battery without cluttering the battery terminals.

 

https://www.amazon.ca/Interrupteur-voltmètre-allume-cigare-adaptateur-camping-car/dp/B01FQODIDU/ref=mp_s_a_1_8?keywords=rocker+switch+panel&qid=1590003537&sprefix=rocker+&sr=8-8
I was thinking of getting one of these and tucking it infront of the cupholders; under the HVAC controls.

 

Just have to find the dimensions to see if she'll fit

 

Started my tray..

 

Damn that looks a hell of a lot better than mine nice job

 

Thanks man! I am a welder fabricator.. I'm scared for all the wiring ahead of me tho haha