Engine Bay Relay Box Installation

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Chained_360

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Hi everyone! It's been a while since I've contributed something to this awesome community so I thought I would share my most recent modification to my '68 Barracuda. The problem started when I bought a Holley 650 with an electric choke and I needed to add a relay to power it. I had a temporary solution that worked (read: I just let it dangle in the engine bay like an idiot), but when I bought CrackedBack's headlight relay kit I decided to add a budget-friendly engine bay fuse/relay panel similar to what most modern cars have.

For $20, I found this unit on amazon and so far it's pretty skookum! Link here: https://www.amazon.com/gp/product/B07MR64XK1/?tag=joeychgo-20
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I thought it was going to be cheap and not that great in the quality department, but it turned out to be rather beefy. The plastic feels nice and is glass-fiber reinforced, so I'm not worried about it getting damaged by the elements or my environmental hazard of an engine. It comes with nice weatherpack gaskets for the relay and fuse terminals, as well as enough terminal connectors for everything plus spares.

Mounting the sucker was another matter. It comes with the hardware and brackets shown above in the photo, including nylock nuts, but the last thing I wanted to do was to drill holes in my original inner fenders. So, I came up with a bit of a redneck-engineering solution.
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Using a random bar of sheet metal I had laying around, I bent a bracket that holds two of the four mounting points. Said bar uses one of the existing fender bolts, bends down to the two bolts on the relay box, and bends down again to a screw I've installed into a broken plastic clip on the vertical part of the inner fender, just above the inner wheel tub. The third mounting point simply shares a screw that holds the washer fluid tank in place, and the fourth mounting point, well... doesn't exist. It's a tripod situation since I didn't want to have two fender bolts not fully tightened, but the relay box is in there pretty solid. I'm not concerned about vibrations or it moving, as I've installed small rubber washers between every bolted connection to reduce vibrations transmitted from the car.

As of last week I have the headlight relays and the relay box installed, and I'm currently working on the choke/USB charger relay. CrackedBack, if you're reading this, your relay kit is awesome! I bought it with some assembly required because I'm a cheapskate, and even then the kit was still extremely simple to put together once I stared at it for long enough. All of the hardware, wires, and shrink wrap is really good stuff, and I can actually see the road at night now! I'll post more pictures and updates as the install progresses. I've tried to keep this upgrade as simple and budget-friendly as possible, in typical student fashion. The bracket I made used scrap steel, and I made it with cheap tools -- no sheetmetal brakes or fancy cutters -- just a drill, an unsecured vice, a sharpie, and a hacksaw. More on that later!
 
Thanks for the positive comment regarding my kit. Good to read it met your expectations.

You could get rid of my relay blocks and mount the kit into that box. Just change the ends and make sure the power feed into the box is sufficient. Always good to power things from relays on these cars.

I have made some kits for the electric choke set up on a few cars. You don't need a big wire for the choke, 16ga will usually be sufficient.

If you want to ask me any questions... fire away. :)
 
My 67 had its OEM horn relay hanging on the core support near the horns. That is now a bosch relay same as others, in the same box. My homemade relay box is on top of the frame rail in front of the alternator. A not so obvious addition. Main power comes off BATT stud of alt'. I did have to drill a couple of holes. Looks like this box is small enough to fit same spot so I'm wishing I had seen it sooner. Anyway... Make yourself a drawing for inside the lid so on some future date you can know which fuse and relay is for what. Old saying... The job isn't finished until paperwork is done applies. Cheers
 
Here's the post I meant to make earlier! I did all this last week but haven't uploaded it yet. I have the relay box installed now and the headlights wired, and CrackedBack I did just that! I'm saving your relay blocks and fuse terminals for another project, they're quality pieces and I'd be a fool to toss them out. I modified your kit just a little bit to get it to fit in the relay box, I just had to reroute some wires and steal some wire from the fuse connectors for the relay box fuses. The whole relay/fuse box kit comes with all the female spade connectors you need for it, and they're alright. My only complaint aside from not having a quality set of crimping pliers is that the supplied connectors could have prongs a little longer. Crimping them to the 12 gauge wire was a bear, but I did it!

Here's how it's laid out so far. I had to cut the mounting holes off of the supplied relays so they would clear the top of the relay box, they came off with a hacksaw quickly. The other modification I had to make was to the relay box itself. The plastic in between the fuse terminals is a little too tall for my tastes, I couldn't get the fuses to seat in far enough to hold comfortably. I took a dremel and milled the plastic down on all of the fuse slots and it fits great now! I haven't installed the wiring for the choke and USB charger yet, I have the harness halfway built but not in. I've marked where everything goes in the diagram below!
RelayBoxDiagram.jpg


I also came up with a stopgap solution for mounting the USB charger itself. I bought it on amazon for about $10, and it's about what you would expect. I haven't tried it yet but it's simple enough. Two USB ports, two terminals on the back, and it comes with some wire and an inline 10 amp fuse that I'm not going to use, I have a 10 amp that will fit in the relay box. I don't want to crawl underneath the dash if it blows!
https://www.amazon.com/gp/product/B01N6S2SNM/?tag=joeychgo-20
For mounting it, I simply removed the ammeter from an oil pressure/ammeter gauge pair that the previous owner installed and made an adapter plate out of the bottom of a can of olives. Tin snips and a file made it work, it's not pretty but it'll do for now!
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