Monday, August 24, 2015

Random Bits and Pieces

Now that the Porsche's in my garage, it's been pretty much a full time avocation. I confess I wasted way too much time trying to find a home under the hood for the contactor box in order to avoid running an extra set of high voltage lines rear to front for the charger and air conditioning compressor. Alas, there's just no room in the inn and I ran that wiring, along with the contactor control wiring, through the firewall and along the floor through the cabin. Not much to see, black on black, and that's good news. It exits under the rear seat back.

I decided to use a 12 volt battery to avoid parasitic loads on the main battery pack while the car is parked. I bought a fresh Bosch group 91 12 volt battery. That's the OEM replacement size, a bit shorter and wider than a standard car starter battery, so it fits perfectly in the battery box with room for the power brake vacuum pump. Both are secured by the single bolt in the center of the space, which happens to be an M8x1.00. I'm getting an education in metric nuts and bolts. This one is a fine thread as opposed to all the ones I had in my bolt box which are M8x1.25 course thread. Only 34 cents, but an hour of trial and error until I finally gave up and went to the home store and rummaged through their hardware aisle.

The rest of the power brake vacuum system was also installed including the pressure switch that controls the pump and the vacuum reservoir. I used existing threaded holes I found in the motor bay that made mounting pretty convenient.

With the battery in place, I ran a heavy duty 12 volt cable under the car to feed the DC/DC converter in the rear. There was no more room in the conduit, so this cable was sheathed in corrugated plastic and run in parallel. When I get the car back to Pro Automotive, we'll put it on the lift and secure it to the outside of the conduit with heavy duty nylon cable ties. 

In the rear I found a well placed hole in the floor board just ahead of the DC/DC converter. It had a grommet that will be opened up to seal and cushion the cable passing through. I was able to clean and repurpose some of the original starter wiring for the connections.

Back in the front, I found mounting spots for the fuses that will protect the high voltage lines for the air conditioning compressor and charger. Again, there was a threaded mount point that made sense.

Finally, a threaded stud on the firewall presented an ideal location for the terminal block for the high voltage motor connections. The 1/0 cables from the contactor box in the rear will connect with the motor cables here. The terminal block is actually a repurposed fuse holder.

The plumbing for the cooling systems needs to be done before the inverter to motor wiring is done, so I think that will be tomorrow's order of business.

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