Side Car "Rebuild" : Fixing the Wiring

So Lori and I purchased this sidecar off of Craigslist. It is a 2015 GSA attached to a DMC Expedition Sidecar made by DMC here in Washington State. It is a beautiful rig that we hope will serve us well in the upcoming years as we hope to get another dog (our golden retriever passed away last year) and enjoy life on the road together with possibly another furry companion.

I knew I had wiring issues. When I purchased the hack, the owner told me he had parasitic drain on the battery and took it to BMW of Seattle to do a quick fix. Unfamiliar with the sidecar wiring, the shop dismantled all the wiring to the sidecar.  Apparently, the dealership simply disconnected the power and ground connectors to "save" the wiring, as there were no visible fuses in any of the sidecar circuits.

I was advised by a couple of folks, including my long time friend and BMW mechanic, Alex from AlyxMoto, to try to and see Mike Paul from LBS sidecars. Which is what we did.

Now, both Lori and I signed up for the Sidecar M/C Safety classes and wanted to use the hack in the class. In its current condition, it wouldn't pass the school's safety inspection as the sidecar had deficiencies: turn signals, brake and running lights were non-operational. And though not related to safety per se, the tub's auxiliary driving lights were dead, and the rig's tilt-adjuster was also non-op

Mike, I was soon to learn, was fanatical about vehicle wiring. He ranted on about the damage and guaranteed electrical problems caused by builders, dealers and aftermarket accessory manufacturers that use or supply those effing, dreaded Scotchlock insulation displacement connectors (other brands are T-Tap, P-Tap, etc.). These may be acceptable on a car or truck, as they are not subject to the shock, vibration, and weather exposure a sidecar sees, especially one marketed as an "adventure sidecar".

The root cause of the dead electricals in our hack, Scotchlock "connectors". Installed by the builder (DMC), they're quick and cheap. The problem was, the size chosen was for the wire gauge the builder was using, which was way oversize for the gauge of the BMW wiring they were tapping into. Thus, there was no insulation support for the factory harness wiring, and this allowed those thin wire strands to move, which cut strands, caused micro-arcing, which eventually cut through the factory wire itself. Here they are (note, Mike cut the brown wire as he started repairs, not the builder or dealer's doing). Note the relay was not secured, also true for all of the sidecar wiring:

 

To do the repairs correctly, Mike had to start at the front of the bike. The original builder had T-tapped into the factory low beam headlight wire to pick up an ignition-on trigger, and that was part of his fix that, and then run the wiring along the same routing as the factory harness. All body panels, the fuel tank, and air box had to be removed to do the wire routing correctly:

 Mike mentions, that,  as is almost always the case, to pick up both power and ground points for the sidecar wiring, there were multiple terminals stacked on the battery binding posts. All were removed and re-routed to dedicated +12VDC and ground busses where he installed in the tail section. As there were NO FUSES for the sidecar circuits, he installed a 30A fuse in the +12VDC power feed to the buss to protect the bike in the event of a short in any of the sidecar circuits.

He then mounted the flasher relay, then labelled everything. All were bundled and secured with milspec, UV-resistant, Thomas & Betts cable ties that have a stainless steel tang to secure the cable tie tail. Connectors were installed where needed to insure any circuit or component could be disconnected for service or replacement without cutting any wire. All connectors are double-crimp, marine-grade, with adhesive-lined heat shrink sleeving.:

 

Here's the completed repair, front-to-back. Note the Deutsch connectors (grey) installed to allow the sidecar wiring to be disconnected rather than cut, for service. In Mike's builds, field service and repair-ability are as important and robustness and reliability. I wholeheartedly agree.

FANTASTIC WORK Mike!!!

As a result, Lori and I now felt it was safe to drive the sidecar. At least we thought so... Stay tuned for another story.

BTW: I passed my test. Lori is scheduled to take her class at the end of May.
 

Please note, all photos courtesy of LBS SideCars (Mike Paull)  

I'm pleased to report, that we have found a home have for all our repairs.this alleviating some of the angst associated with sidecar maintenance, repair and ownership.

When you get great service, it deserves to be recognized... 

LBS-Sidecars USA, LLC is proud to be the North American affiliate of LBS Sidecar Technology. Fabrication of sidecar kits and components is done in Europe. Final assembly, customization, installation and test is done in America. We also offer URAL sidecars, and are an authorized Touratech dealer (USA only). Because our production and build capacity is limited, we currently offer components and builds for BMW motorcycles only.