Monday, October 11, 2010

Top Transplant - Relocate Wiring and Overhead Console Project

Here is more of my retroactive documentation. In this installment, I tackled the relocation of the overhead dome/map lamp and add an overhead switch panel.

As always, more/bigger pictures on my web album.

The main push for this part of the project was to deal with the aftermath of having removed the forwardmost structural rib from the Astro van roof. The GTRV steel reinforcing ring took care of the structural element, but there was also a couple of wiring harnesses that passed over this rib, one of them to feed the forward dome lamp and map lights that also hung here. The GTRV donor van had an aftermarket RV dome/map light in the overhead space between the reinforcing ring and the windshield/rearview mirror area. I liked this placement, but I was pretty sure I could make mine look more factory by reusing the original GM light assembly.

Like the GTRV solution, my implementation began with a piece of aluminum sheet. I didn't like the way theirs was sort of bodged on, though, so I started by bending a mild angle to fit the top of the windshield header. This gave me a better flat-to-flat surface to drive a couple of sheet metal screws though. The bend was mild, so I wasn't worried about cracking, but if there had been much more to it, I would have felt compelled to anneal the sheet before bending. Behold my super-quick-and-dirty metal brake, basically a few pieces of angle stock in a vice. The top pieces clamped on with c-clamps keep the bend straight and prevent me from over-bending and risking cracking.

Next I started laying out placement of the dome lamp housing, as well as a plate to mount some switches. Is that carbon fiber? Yes, it is. Why carbon fiber? Because when you're an ex-Battlebot builder you've got big sheets and even bigger piles of scrap CF plate lying around in your shed, looking to get used. Plus, its nice for mounting switches because its a bit thicker (and more rigid) than a thin metal sheet but is still easy to machine with a dremel and a file. The extra material thickness seems to hold the switches more tightly.

Zardoz is displeased. Actually, these are clearance holes for the wiring coming off the backs of the switches. The carbon plate is spaced off of the aluminum mounting bracket to allow for the thickness of the headliner (once reinstalled), but the wiring needs to go back up under the headliner to the rest of the chassis loom.

Here you can see the how the bracket fits onto the reinforcing ring and windshield header. I'm extending the wiring harness that used to follow the roof rib. I pulled matching-color wiring from the donor van to extend all the wiring, so there would be no troubleshooting hassles down the line. All the new harnesses were sealed with weather-tight heat-shrink crimps and then wrapped in that sticky cloth wiring loom tape. I even wrapped-in the factory clips so the wiring loom is secured to various bits of the roof structure as it routes along the van. All of this will tuck up under the headliner when reinstalled.

Here is the switch plate, ready to install. At this point in the process, I was still planning to use the electric actuators to lift the top (see previous post), so there are two momentary rocker switches for the actuators, plus a DPDT switch to lock the armatures, plus one spare. The divorced actuator switches were so that I could fine-tune the tent tension in case the motors didn't lift at the same speed. I ended up chucking this design, though, so I now have a really cool carbon fiber switch mount with four unused switches.

And the dome lamp and switch plate installed to the mounting bracket. The dangling blue connectors were the leads to the actuator motors so that I could use the switches to move the actuators prior to final installation. I do wish I had just mocked-up the (complicated) switch wiring onto a temporary board before I found that the actuators would have to be scrapped. It might have saved me some effort here...

And one final little project. I made a bend-template to make a bracket to hang my ScanGauge from the windshield header above the rear-view mirror. I ran the cable up the A-pillar and now the gauge hangs in a comfortable field of view above and to the left of the mirror. The bracket is from a chunk of scrap titanium, bent on the same bending rig shown above. Yes, I have scrap titanium too. This chunk was originally salvaged from a British Heavyweight that fought (and lost) in Las Vegas (Battlebots Season 2), and had since been used in a variety of my beetleweights and flyweights in bouts all over the Southwest.

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