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Garnet wrote:By control do you mean resistance?
This is a helpful test elswhere. 100w headlamp bulbs spring to mind. You do a drop test across the high/low switch with the 55/60 bulb and then try the 85/100 bulb. That will tell you weather the switch can handle the load, or if you need a relay.

Ken in Oklahoma wrote:I've been making my own battery cables for a while now. The result is, IMNSHO, much better than new stock BMW cables.

For the cable part I use #4 AWG "lead" cable, or at least that's what I think it's called. It is commonly used for connecting the arc welder “high” to the electrode holder. The cable has a rubber insulation (not PVC or other plastic) and has fine wire strands for flexibility. This is a wonderful cable, if you've ever wrestled with the stock BMW cables trying to get them to lay correctly. It naturally costs more than cheaper cable, but you will end up with a battery cable that will cost much less than the eBay cables.

I cut the ground cable to length a few inches longer than the stock BMW cables. This gives me some flexibility (no pun intended) if I use a non stock battery with the positive and negative posts on different sides from the stock battery. The longer ground cable also allows me to use a different grounding point on the L/H side of the transmission, thus eliminating the possibility of stripping the threads in the usual location at the speedometer take off point.

For the cable ends I use plain #4AWG ring terminals. So far I have only found these in copper. I would like to find the steel version for durability.

Strip about a half inch of rubber jacket away and you're ready to fix the terminal onto the cable. This is where you need to make a special tool to do the crimp that is required. I measure the O.D. of the ring terminal barrel and find a drill bit of the same diameter or slightly larger. Then I drill a hole in a piece of hardwood, say about 1/2" thick. Aluminum or even steel would work fine too.

Now I cut half of the hole (or less) off the hole I just drilled away, leaving a half hole. This will be your anvil for crimping the terminal onto the cable. I hold the anvil in a vice for the actual crimping operation.

Now you need to make a punch to do the crimping operation. For this I ground the end of an old chisel, rounding it so that the indentation in the ring terminal will be smooth. A mild steel rod with the end ground appropriately would work too.

You’re already figured out the rest. You put the terminal on over the bare wire, hold it in place on the anvil, barrel split downward, then smack the barrel part of the terminal with a hammer and punch. You’ll have to judge how much is enough.

Now I will hold the freshly installed terminal in a vice and solder the connection. Rosin core solder of course. I hold the terminal with the cable pointing up. That is so gravity will help wick the solder in the correct direction. I use a small butane torch with its precise flame for heat. A large soldering iron would work too, and you wouldn’t have to be careful of the flame. Be careful because the solder will still wick upward and you will have stiffened about an inch of the cable before you know it. You can guess how I figured out this bit of wisdom.

Putting some shrink tubing over the junction will make the job look professional.



Ken

Duane Ausherman wrote:dougie, this is an excellent example of thread degradation. However, I must confess that it is obvious that both Doug and Garnet have a considerable understanding of electrons and how to play with them. Were we all around the same campfire, we would really bore people, but have a lot of fun.

I value all of you folks and while I can be quite cryptic in words, my speech is better. I would never want to walk away with bad feelings over these areas where we muse forever. In that case, I would be an addict without a supply. Not good.