8- The Build (part 3)
Power Steering
In an ICE, the power steering pump is belt driven off the engine. Some cars have electric pumps that provide hydraulic power for their power steering, ideal for an EV. The 2000 Toyota MR2 had such a pump with a controller and reservoir all in one unit. For wiring directions, there is a great entry in the wiki on DIYelectric car. Photos and instructions can be found here:
http://www.diyelectriccar.com/forums/showthread.php?t=19505&highlight=toyota+pump
There's a nice empty well now on the driver's side of my motor compartment, and my MR2 PS pump fits in there nicely. I fabricated a mount out of an old cutting board and bolted it to the frame rail and a bracket supported by the inner fender. I did need to have a custom pressure line made by Industrial Hydraulics, Inc. in Indianapolis. I like going local whenever possible, and they really took the time to find a solution for me. The low pressure return line can be found at just about any hardware or auto parts store.
Power Brakes
Cars get their vacuum boost from the ICE typically. OHMer will get his vacuum boost from a 12volt vacuum pump attached to a vacuum reservoir. Also, the zx2 gets power to open and close all the ventilation ducts from vacuum, so I'll have to put a splitter in the vacuum line and draw some off to keep these operational.
Battery Charger
There is an onboard charger attached to the other end of my "fuel plug" so that I can charge the car's batteries anywhere there's a household plug. It works pretty much like any battery charger, just a bit bigger.
Control Box
I have a small electrical box that holds my ammeter shunt, circuit breaker (will be used as an emergency off switch) and contactor. The shunt sends a signal to my interior ammeter telling me how much juice I am using up at any given time. The contactor is controlled by the ignition switch so that the car can only be driven when the key is put in the ignition and turned to "run".
I've added a couple of things to my control box. The zx2 came with an inertia kill switch for the fuel pump. I decided ot keep that and use it for my contactor. Basically, if I'm in a hard enough accident, the switch will trip and interrupt the power coming from the ignition, thereby disconnecting the main contactor. The car will have no power going to the motor at that point. Also, I've installed a charger interlock relay. This will not allow my to engage the main contactor if I am plugged in charging anywhere. I wouldn't want to drive around with an extension cord hanging out my fuel cap! The metal and green plastic lever you see is a way for me to turn the circuit breaker on and off when this box is closed up and the controller is on top of it. It's good for working on the car or to stop it if all other methods fail. There will be a connector that I can access from the driver's seat.
Here is the dc/dc converter. It takes the 120v power from the main battery pack and converts it to 13.7v for the cars accessories. It will also charge the car's 12v battery which I have decided to keep for backup and extra power. I bought a cheap, small cutting board and mounted it to existing holes on the strut tower - then mounted the converter to it with small spacers for air flow. It won't put off as much heat as the controller, but a little bit of cooling air couldn't hurt.
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Page 9 - OHMer - post conversion
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