MG Sports Cars

I need to run a hot lead from my battery up to the remote battery posts I put up by the slam panel. Am thinking of putting conduit through the outter sill like Ted did on Dan's car. Are there vertical pieces in there that'd get in the way?

Yes. There is a brace just over the jacking point. We were able to run the conduit because we were also replacing the outer sill, making access to the brace possible. If you look closely, you can see the spot welds for that brace.

Hidden wiring can be aesthetically pleasing but I often wonder about accessibility if there is a problem.

If you run hidden wiring it's a good idea to do it in such a way that it can be pulled back out for inspection/repairs and reinstalled. That can be done, but it generally means using a much larger size conduit than you had visualized, using the smallest possible wire ends, and eliminating branching, wire-ties and wrapping, similar to good industrial electrical conduit practice. Once you are there, you have to wonder if pvc conduit might not be a better choice. And then, what about optional conductor types? Bare buss bar for instance. Welding cable. Other materials and methods? Waterproofing? Junction blocks for the wires that go through the conduit? Suddenly you are re-engineering the entire electrical system. That's not a bad thing, I'm just pointing out where one seemingly small change can lead. Everything you add brings more bulk, weight, cost and complexity with it. If that fits within your vision for the car it's all good. If it isn't a clean fit, reconsider.

The stock arrangement isn't bad. The original cable can be replaced with a much heavier one. A high torque starter lightens the load. An additional cable can bring the power from the starter to a remote terminal point, or more than one, relocating the power feeds for the rest of the system. Running the harness under the carpet is another option that is easy to do, unobtrusive, keeps it clean and accessible, and out of sight. But you wouldn't think you'd want the main power cable there.

Modern practice seems to be to use all reasonable methods to keep oxygen away from the conductors, connectors, terminations and such. Many times this is not practical but where it can be done it will make the wiring much more reliable. Even the fuses and relays could benefit from it. Eventually we will see gas sealed components used in cars almost exclusively but we're still a long ways from that. There is a lot we can do though. Substitute modern connectors for the old bullet connectors, use wire with cross linked insulation, etc. There's no reason why a new wiring installation shouldn't last 50 years or more.

Jim

Quote:
[Modern practice seems to be to use all reasonable methods to keep oxygen away from the conductors, connectors, terminations and such]
......exactly the reason that, a few years ago, I started to use dielectric grease on all my connections.

Points taken on being able to pull the wire back out to inspect.

I looked at my car & it appears the brace for the jacking point is in the inner sill, not the outer. This pic seems to confirm. Anyone done a sill replacement recently enough to remember for sure?

If that pic is right, running a conduit through the outer does seem to cover both bases but it'd be a lot of work & might be more than I need to do.

I hadn't throught about routing from the starter up to the remote posts, I'll have to look at that to see where the wire would end up vs. where my exhaust runs.

I mounted the post on the firewall ledge & connected it to the solenoid terminal. It's ideal for battery charging & jump starts. On a LHD car this arrangements would be even easier. mgbazza

I'm coming in late on this one but WOW! Either I am Channelling Jim B or he is channeling me.

I would like to add that my 1/2" conduit is very tight and I am considering a larger type in the next project. This is up in the wheel wells, not in the rear.

Finally, we use a junction block with a 100 amp fuse in it. You can find a number of pictures of this on our website in the passengers footwell.

-BMC.

I hadn't come back to this in a while... good input. After thinking about the wiring that runs from the fuse panel (which will be in the cockpit somewhere near the firewall) to the back of the car, I decided there's not enough wire running to the back to warrant the conduit thru the rocker. I shaved the side markers & back-up lights so only really have 5 things back there (trunk light, tail lights, turn signals & license plate lights).

Rob, fuel pump, fuel gauge sending unit? Two more on most cars from the front to rear.

Good call Bill... I've got those too of course!