Hot Rods Fuse panel and battery in the trunk tricks

Hi guys, I am helping a buddy out by wiring his super cool traditional early caddy powered 30 model A coupe.
He has an EZ wire kit and has mounted the Optima style battery and fuse panel in the quarter panel in the trunk. So my question is apart from most likely having to lengthen all the wires and loosing the labels due to lengthening is there any other pitfalls in doing this?

 

The wiring does not care which direction is going.

Just buy good quality wires, of the same color jacket, and correct gauge.

 

^^^^^ X2

 

I understand wanting to access the Fuse block without standing on your Head. That's why over the last 10 years or so I have been making it so I can drop the Fuse block down in my hand to deal with them and move them to center or more to right. That way I don't need to lengthen any wires or stand on my head.

 

Just take voltage drop into account when you lenthen wires. You may have to increase the size to compensate for a longer wire run.

 

X2 on this. A wire that is adequate at one length can easily become too small when lengthened. That's the reason most cars have the majority of wiring clustered in the front of the car. If it were me doing this, I'd bump all the wires up at least one size right out of the fuse panel.

 

I got a chance to utilize my hinged fuse panel under the dash yesterday. After upholstery was finished I installed my radio and accidentally popped a 10 amp fuse in the panel (note to self: turn off battery switch before installing electronics). Anyway, one thumb screw and the panel dropped down. Out with the bad, in with the new. Fold it back up and no wiring visible. Doesn't get any easier or cleaner.

I thought about installing in the trunk but that is a ton of wiring moving to the dash and front of car. But if you do go that route most companies sell a long wire version of their install kit for this purpose. That was you don't have to chop and extend your nice new wires.

 

I want to "hinge" the fuse panel on my next project. Any hints pictures / suggestions?

 

I like the hinged idea under the dash also, but in 30 model A with a functioning cowl fuel tank there sure doesnt seem much room to hide the fuse panel. My buddy has installed a hinged panel in the trunk quarter panel though.

 

What about putting it under the seat?

 

These are not very good pics but you get the idea. I drilled and tapped a mounting bracket that I welded to the firewall during construction. I made a steel plate and used a SS piano hinge to mount it using 4 short bolts and Loctite. The panel is inboard of my column and folds open just short of the top of the column.

My car is complicated with a few accessories and several relays, all of which is contained in that one panel. All the wiring is ran up to the cowl and then down to the fuse box allowing it to open and close. The cloth wiring is headed to the engine (gauges, coil, fan etc) and front light, signals, horn, etc where I didn't want plastic wiring showing.

Folded up and stowed you can see the hinge and the plate that I painted and clear coated body color. The plate attaches to a bracket and nut zert that bolts to the under side of the cowl to a stud I welded in also prior to paint.

 

Are you saying the wires are not long enough for the panel to be mounted in the truck? HRP

 

In the last 4 or 5 custom jobs I've done, I recommended the fuse panel be located on the passenger side, inside the right kick panel.
This not only moved it away from the 'busy side', but also provided a safety feature in case of a roadside necessity...traffic roaring by day or night can be intimidating.

I only mention these factors for those who live out of state...Here in California, it's against the law to text, drink, and talk on cell phones while driving...so, we're safe!

 

Also using a Butt Connector mid stream in wire creates resistance. That said and the mention of upping gauge size from the actual Fuse Block it sounds to me starting with a bare Fuse Block would be a better way to go?

 

I think people get far too fussy about wiring in cars.

I build prototype cars for an OEM, where we take an existing vehicle, and add about 400-lbs of extra wiring into it, in order to facilitate the desired, mission-critical, and life-safety functions. These functions are of a far higher gravity and significance than any that any rod or custom .

Try to imaging taking the interior out of a car, and finding nothing but wire, and hoses, in every possible location.

Every connection, save for those directly connected, via solder, to a board, is crimped, and there are butt splices in about 60 locations.

All of this wiring is of a gauge that would astonish many of you, as you would consider it under-rated for the job.

Unless you have a 50-foot long car, bumping up wire gauge, on anything but the battery lead, or alternator charge lead, is unnecessary. Just don't buy a junk harness to begin with.

But hey, I'm no expert.

 

I did my brothers 40 ford almost 10 years ago, zero problems, fuse box, in trunk, battery in trunk, ez wire kit. radio in package shelf, vintage air, everything works fine. getting ready to do mine soon. if it were a station wagon, or a limo with xtra long wiring I could see voltage drop being a factor.

 

A properly-crimped connection won't add any measurable resistance to a circuit. You'll likely to have more resistance at a push-on or screw connection.

I've said it before and I'll say it again; I haven't seen ANY 'universal' aftermarket harness that has properly-sized wire for more than a bare-bones install. They 'emulate' what a 'basic' OEM harness is, and the OEMs don't do any more than the bare minimum needed to keep costs down. And they don't always get it right; I read recently that the new rear-engine Corvette will be delayed because GM found out the harness was 'inadequate' and needs a redesign... instead of moving the fuse panel to the trunk, they moved the engine...

 

A Model A is a pretty short car, I'd think a standard generic kit would have long enough wires to run out front. There are kits made to locate the panel in the trunk for street rods. I can't recall who makes one.

 

Mine is on the drivers side, inside what would be the kick panel, IF there was a panel there. Easily accessed if needed. But the passenger side would have the benefits you mentioned. In any case, on a Model A it seems like either sides is a natural place to put the fuse panel, why would you run it all the way back to the trunk?

 

In my T coupe I mounted it on the passenger side kinda like Bandit Billy. Built a bracket on the inside of the firewall for the hinge so no screws were visible from the outside. Cut a piece of sheet metal to run back to the bottom flange of the dash with two #10 nut serts and mounted the fuse panel to that. When in place it's nonvisible and when open the fuse panel is vertical and easy access.

 

According to NAPA a regular 2 gauge battery cable looses 3 amps per ft. A 2 ought, welding, cable, only looses 1 amp per ft. A 3 ought cable looses .4 per ft. So, depending on what kind of cranking amps your engine needs and the distance from the trunk to the starter you might want to use larger cable and wire.

 

In my 34, I also mounted the fuse panel under the dash, passenger side [so I don't have to fight the steering column] on a hinged panel. I also used an EZ wiring 21 circuit harness. I mounted the switches, lights and starter button on the header panel above the windshield. Had to splice a few wires to reach but not many. I used a small panel from a 90s buick to mount my relays right next to my fuse panel. Relays switch the headlights, horn and electric fuel pump.

 

Wire doesn't 'lose' amps. But undersized cable will have excessive voltage drop, which will affect current draw. How that drop manifests itself varies with the type of load; a non-motor load will see less voltage and current, while a motor load will draw more current. More current, more voltage drop and it quickly becomes a vicious circle. And that 'dropped' voltage just doesn't disappear; it's converted to heat. When you see a burned wire or connection from whatever reason, what you're really seeing is too much voltage drop.

 

For what it's worth, I got a Painless kit made for trunk mount panel and battery, largest quantity of circuits, didn't have to extend any wires, ZERO problems. Added two Ford type starter solenoids one isolates everything (key on) and feeds the second solenoid that pulls in the starter so that huge ass welding cable going to the starter has no power on it except for starting. It's a safety factor in case I ever get T-boned. Starter cable is fed through a three-quarter inch PVC pipe to the front of the car. Some pictures and commentary at:
https://49fordcoupe.smugmug.com/Wiring-the-Car/

 

Being in NZ , BMW E36's are plentiful at "pick-a-part" , so go and vulture the heavy duty battery wires from one of them [They have a trunk mounted battery]
They also have a neat little junction box on the inner fender for jump starting.[all the fuses,etc can be taken off at that point]
About $20 from "pick-a-part"
[here's the junction box]

 

I've only done two cars to date, the 37 Fordor's fuse panel was by Haywire and it was mounted just over where the tranny tunnel meets the inside of the firewall. Since those cars are so tall, the firewall is huge and the box was easily accessed from either side. It also had a nice snap on cover. The Ron Francis deal in my truck is mounted up over the steering column behind the bottom edge of the dash and is, sadly, not "painless" to access. But there was no room in the kicks. I should have done the same as the 37, mounted it over the tranny tunnel some how. To compensate, I made sure to use those new fuses that light up when they blow. So I can easily see where the problem is. So far, I've only had one fuse go, and it was a long time ago. For my 29 coupe I'm going to try something more racy (but still covered with a snap on panel of sorts) and put it in a super easy place to access - more like a vintage race or rally car - where key fuses and relays are practically at arm's reach with the driver still seated. In the arm rest? Just ahead of the shifter? At the same time, I plan to run the wiring as high as possible in the car (ya never know when you have to ford an intersection or creek these days) so most of the front to rear wiring will be on top of the tranny tunnel anyway. I think I can hide it all in some sort or recessed channel on the top of the tunnel. That's the plan right now, anyway. Gary

 

Three amps per foot?!?! Man, wouldn't the wire positively glow at that rate, like a filament in a bulb?

 

Man, the thing NAPA is trying to say is the resistance per distance. But 2 amps per foot is way out of the rocker. All wire has resistance per 100 ft. its a standard measurement, this wire size calculator will help others maybe with their quest for this thing called wiring.

https://www.wirebarn.com/Wire-Calculator-_ep_41.html

I size every wire on my build off my Rolodex in my head, Amperage and length always get figured in.But this is a good way to help you figure out what you may need.

 

I have been a convert to putting fuse box in trunk for some time now. I understand hinging the panel under the dash for easier access, but you still have to contort your body to work on it. I'm just trying to explain that the older I get, and more arthritic I become, I look to make things easy for myself.

 

a early 90 full size ford the fuse panel is hinged from the factory at the bottom of the dash