Question about mounting wiring and electrical components

I am getting ready to wire my 31 roadster using the sac vintage kit. I am looking at places to mount my fuse block, terminal blocks, flashers,etc. the problem is that there really isn't much in the way of attachment points under the dash aside from the sheet metal itself. Do you guys build a wood or ABS plastic "shelf" as an attachment and isolation point for said components? I am also considering mounting the wiring under the seat, but am somewhat sketched out about doing that for some reason.

Thanks

 

Under the seat, behind the seat, in the trunk.......any of those locations can work out well......and keep the not so glamorous parts out of plain sight.

It's just electricity...it'll go were you 'plumb' it.

Ray

 

Get a fuse panel ass'y from a 90's Taurus/sable. They mount under the dash and fold up under the dash. Mount your fuse panel to this. I mounted mine on the pass side so I'm not in the road if I have to check a fuse.

 

What kinda of car??

I just mounted one up in a 58 chevy pickup, and I drilled two holes through the firewall and used two nice polished stainless allen head button screws with the nuts inside. Looks pretty nice to me and doesn't mess anything up.

You could easily mount a small piece of 3/8" mdf to the place you have room for, and the mount everything to that?

 

Sorry CHaddilac..... But DO NOT use mdf. Any moisture at all and it will crumble. Get a pice of 1/2'' plywood, cut out the size piece you want and seam seal/liwuid nails the piece to the inside of your firewall as high up as possible. Then, just screw your fuse panle to the wood.

 

Thanks for the responses so far. From a practical standpoint is it better to send wiring to a dash mounted panel that is further from the battery or have the panel closer to the battery but a greater distance from all the components?

 

BTW, I plan on using a ford starter solenoid mounted in the rear near the battery if that makes any difference.

 

How is all this stuff grounded if you use a plywood base? Bob

 

I would imagine all ground would have to be run to a grounded distribution panel, no?

 

As for "which is better"...electricity travels at the speed of light, so distance is only a factor in potential voltage drop over longer wire lengths. However, with a car a compact as a '31 Roadster, even that is minimal and can disregarded in my opinion.

Normally, having battery nearer to the starter, and alternator, is better because of the high amp loads carried by those wires/cables. But if you are committed to having the battery in the rear, and that is also common, the rest of the wires are piece of cake.

The main concern I would have is to be sure the wires are routed carefully to avoid chafing or damage in normal use and absolutely have then fused for only as much amps as needed for the job each is doing. That way, any short circuit will do no damage other than to the fuse as intended.

I think I would use some grounding wires in the system, not relying solely on the body for ground circuit.

Ray

 

We raffled off a 31 roadster with an Olds in it for the 1978 Nationals in Columbus. It had a battery in the trunk but had trouble starting when it got warm. We ran heavier battery cables to solve the problem. I've never had a problem with distance on anything with a 12V system other than the starter cables. Distance is not a problem except for high amperage wiring such as the battery cables where the distance causes added resistance. Any other system should work just fine.

I don't run a bunch of extra ground wires around the car but I don't usually mount electrical parts on wood either. An aluminum plate with a ground wire under the parts on top of the wood will complete any circuit.

 

I like the aluminum plate idea for mounting components. And I would suggest locating your fuse panel in a location where you can easily access it, for troubleshooting or adding more circuits in the future. You could always fabricate a cover of some sort to disguise it if it's in a spot where it can be easily seen. Of course, that's just my opinion...and you know what everyone says about opinions.

 

Thanks everyone. Tommy and Hnstray, I am going to use the remote ford solenoid to address the issues that you botH brought up. I like The idea of The hoT wire being live only when activating the starter. I also hope that it will help avoid any hot starting issues.

 

yup you just run a ground wire for it

 

I have the battery and Ford solenoid located behind the seat area in my '32. I am using the basic drag-race-intended layout designed by Mark Hamilton of MAD Enterprises many years ago, where the battery starter cable is hot only when starting. The main feed goes through a +/-100 amp fuse (depends on your requirements) that powers the entire car. Like cafekid, I used 1/2" plywood that covers the upper part of the firewall where the fuse panel, pos./neg. power lugs, relays, fan controller and power distribution strips are all attached. I'm also using a R F grounding system, where everything has it's own ground back to the battery.
Having the electrical under the dash can leave lots of valuable room for storage under the seat, important in a roadster!

 

There was some small square tubing bracing at the firewall that I attached aluminum plates to mount my gauge terminal block,and fuse block

 

the issue is not where the solenoid is mounted. The issue is the voltage drop that occurs in a long run of battery cable. The voltage drop will still be there no matter where the solenoid is mounted. The voltage drop occurs in the negative side of circuit also. That is the problem with mounting the battery in the trunk. The Ford solenoid trick is to replace factory solenoids that get heated up from headers like Chevrolet's.

 

Steal a trick from Ron Francis Wiring. Their 24/7 fuse panel has a magnetic mount. Use wharever panel you want, mount it to a steel plate, glue a strong magnet to it and hang it whereever you want! It worked for me.

Here is a quote from the Ron Francis website: MOUNTING: The ‘quick release’ magnet system will hold the panel under the dash until you need to check it. Just drop it down to work on it, since there is approximately 18” of movement in the wires for ultimate flexibility. Never has servicing a fuse box been any easier!

 

Why would you have moisture near your fuse panel? If that's the case you got bigger issues!

here's how I did mine...








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I mount it on a small piece of 1/2" plywood glued to the firewall with automotive structural adhesive, yes I have to run a ground wire.

 

That looks very nice!

 

My reasoning for mounting the solenoid near the battery in the rear was addressed by V8 Bob. I would like to keep the hot wire to the starter dead except for when cranking the engine. I feel that the shortest length of live wire would be the safest.