Battery Cables

[KellyVB 75R90S]

Was wondering if anyone use's 2 neg battery cables, 1 on ths trans and one to the frame ? I was doing that and wonder if it makes a diff.

[gspd]

I eliminated the ground wire going to my transmission (speedo cable bolt) decades ago.
I installed a 4g wire directly from the battery negative terminal to a starter mounting bolt, another from there to the main frame near my coil.
Made a hole in the top of the starter cover to do so.

[KellyVB 75R90S]

I have a 4ga to the trans, and another going to the coil bracket. These are fairly new cables. I read somewhere that it was good to have a case ground and a frame ground. How about dielectric grease on connections? I was thinking about using some Liqui Molly LM 508 copper based anti-seize on connections

[Kurt in S.A.]

I think where you want extra grounding is at the alternator. I bought a "spider" harness from Motorrad Elektrik which installs under the front timing cover. Can't say it helped much, but I'm sure it didn't hurt.

Kurt in S.A.

[KellyVB 75R90S]

Will have to look into that. do you have a link Kurt ?

[gspd]

Kurt said: " think where you want extra grounding is at the alternator. I bought a "spider" harness from Motorrad Elektrik which installs under the front timing cover. "

The alternator itself is grounded by its 3 bolts, hard to improve on that.
The 'spider' harness if I'm not mistaken is for diode board grounding.
I switched to solid diode board mounts to eliminate the wires.
The rubber mounts can detach and cause the board to contact the front cover and cause a short.
https://www.boxer2valve.com/stainless-d ... s-set.html

[Rob Frankham]

This may be of some interest...

https://robfrankham.com/about-earthing

Rob

[Kurt in S.A.]

Well, I did say "...at the alternator...". Last time I checked, the diode board was also at the alternator! Yes, I also did the solid mounts.

I checked Motorrad Elektrik's site and don't see the harness...I got it many years ago. I seem to recall I had some corrosion on the three-wire cable that went from the alternator output to the backside of the diode board. I think I called Rick and he made me the three-wire cable and I also had him make me the grounding harness...maybe I ordered it "off menu"! Snowbum discusses the harness and mentions one or more service bulletins which came out regarding the issue. Search this page for "spider"...it's near the middle of the page:

https://bmwmotorcycletech.info/diodebds&grdgwires.htm

Kurt in S.A.