Battery cable??

[PeterC]

Mine shorted shortly after I hit a bump which moved the exhaust clamp that pinched it and broke the insulation. It was perishing anyway.

I'm thinking a #3 AWG copper.

Oh, it's a 1964

Any better ideas?

Thanks

Peter C

 

[dklawson]

I don't think you'll find #3 AWG cable.

I have not measured the cables but I know that you're correct... it's somewhere between a #4 and a #2 cable.

The maximum current rating of a cable is based on its jacket material and the size of the copper conductor. Bigger cables aren't always mandated. In the case of cars like the Mini, the main battery cable only carries high-current during starter motor operation... which is very short in duration. Therefore, while a #2 cable would be great, a #4 AWG cable will work without issue.

I suggest you measure the jacket OD of your car's main battery feed cable. Using that information go to a local welding supply company and buy about 12 feet of a welding cable having a similar (close) OD. If they have a #2 cable with a jacket OD close to what's on your car... buy it. If not, get the #4 and know that it will also do the job. If no welding supply stores are in your area, visit www.mcmaster.com and search for "welding cable". Select the largest cable with a jacket OD close to what's on your car. Again, if a #2 will fit use it, if not, get the closest #4. McMaster will sell to anyone with a credit card and the shipping has been reasonable. Browse for just about anything else you may need and add it to your order. They sell virtually everything.

All of this information assumes you really MUST replace your cable. There is an alternative. If the cable is not burned through, it is possible to repair it. Carefully cut away the burned cable jacket trying not to disturb the copper. If you have an electronics supply store near you , buy a length of large ID heat shrink tubing. You'll need a piece large enough to go over the ring terminal on the solenoid end of the main cable. Once you've removed the burned jacket material slip the heat shrink in place and use a heat gun or gentle flame from a propane torch to shrink the tubing in place. If you don't have access to heat shrink tubing, buy a fresh roll of quality electrical tape from the hardware store. While you're there, also buy a can of the brush-on liquid vinyl. Sometimes this is even marked as "liquid electrical tape". Degrease the cable and wrap the burned area with several layers of the electrical tape. Build up the tape thickness to more or less restore the OD of the cable. Now apply a layer of the liquid vinyl over the electrical tape including at least an inch of the un-damaged cable jacket. Once that application dries, apply a second coating. In the end you'll have a water tight repair of the jacket.

Regardless of whether you repair or replace the main cable, make sure you anchor it securely in a manner that prevents the cable from contacting the exhaust. "P" clips are good for this but you may need to add some additional anchor holes to the subframe for mounting points.

 

[PeterC]

Thanks Doug. I was able to buy #3 at a local wholesaler, and the appropriate ring terminal. $18.00 for 10 feet. It has a pretty stout jacket. The old cable had a few bare spots, after de-oiling, and the principle cause of my failure was nearly through.

I tested the problem by disconnecting the suspect wire and substituting a jumper cable lead.

I plan on doing the work this weekend, but I suspect all will go well. Fitting it back into that channel on the floor pan may prove interesting. I will probably start cleaning that part, and end up with shipwright's disease.

Peter

 

[dklawson]

Wow ! You found #3 AWG? That's great! I'm going to remember this thread for future reference.

Don't forget to put that old cable in recycling. It's a lot of copper to just throw in the trash.

I understand completely about shipwright's disease. That's what I'm dealing with now with our project Spitfire.

 

[Hedgehog]

Peter, where'd you get the #3? I'm going to need it for both the Cooper S resto and some for the racecar.

If you need a hand give me a shout. I'm around most of the weekend. Otherwise, stop by D & D's Firehouse on Saturday evening and I'll buy you and Jane a beverage.

 

[PeterC]

David, I keep meaning to with Pat and Penny. Soon, maybe this weekend? Anyway, got the wire from Lappin around the corner from me.

Peter