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JeepEV: Electric Vehicle Conversion Project
Instrument Panel

Ideas about the Instrument Cluster:

     Instrumentation is very important. It provides the driver with information about the status of the vehicle's electrical systems. I've always liked it when vehicles have lots of lights and gauges and other "eyecandy", so I'll have fun with this part of the conversion!

     The Jeep's stock dash board had all the basic gauges: Speedometer, Tachometer, Coolant Temperature, Oil Pressure, Fuel Level, and a 12-volt voltmeter. With the exception of the speedometer and tachometer, the other instruments would be of no use to an Electric Vehicle. Instead, in an Electric Vehicle, you really want a voltmeter for both the low and high-voltage systems, an ammeter, and the speedometer and odometer.

     I thought about the best way I could convert the dash to display the info I needed it to about the Jeep's electrical system. One idea I had was to build circuits that would allow me to show this information through the Jeep's existing gauges. The gauges all read the resistance of their respective circuit, so as the resistance changed, the gauge would move. I soon decided this wasn't a good solution as I'd have to re-label the gauge faces and because the gauges were the crappy (not aircore) kind which aren't that accurate.

     What I decided I really wanted to do was to make a completely digital dash which displayed all the information about the Jeep on an LCD screen. Ha! Keep dreaming, Nick. Unfortunately, making something like this is currently beyond my level of electronics skills, and probably not cheap either. But someday...

The First Dash: An Analog Instrument Cluster (OLD)

     Well, when it came time that I needed gauges, I set aside my hopes of building some form of a digital dash and began work on a *temporary* analog dash board. I already had purchased three gauges: a 60-160volt voltmeter, a 9-17volt voltmeter, and a 0-400amp ammeter.

     I began this project by removing the old instrument cluster from the Jeep. The instrument cluster consisted of the gauges themselves and an "idiot light" section, which has warning lamps for the seat belt, parking brake, 4x4, upshift, etc.. Next I removed the small gauges on the sides so that I could remove the speedometer/odometer. The speedometer/odometer in this Jeep are mechanical and are driven from a gear in the transfer-case. I decided to reuse the speedometer head not only because it would be easier than searching for an electronic speedometer sensor, but also because the odometer has all 409,000 or so of the gas engine miles recorded on it.

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The old Jeep instrument cluster is removed from the
vehicle, of which the speedometer head is removed from.

     I then measured the old instrument cluster casing (minus the idiot light part), and cut a piece of MDF board I had to the correct size with a jig-saw. I had to shape the top and bottom of it to have "tabs" which are where the screws held the old instrument cluster to the dash frame in the Jeep. Then I needed to cut round holes for the three gauges, a round hole with one flat edge for the speedometer, and a hole for the wires for the Raptor controller status lights to pass through. once the holes were cut, I painted the MDF board black, then installed the gauges.

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The new MDF panel is cut and painted. Then
the gauges and the Raptor LED module are mounted.

     Then, after soldering the common wires for all the gauges together, I hooked the instrument cluster up and installed it in the Jeep. The Speedometer cable screws into a hall effect sensor under the dash which used to be used for the cruise control, then that sensor is connected by cable to the transfer case and the speedometer gear. The ammeter is wired to the shunt, the voltmeters are hooked up to their respective systems, and lastly the Raptor status LED module was plugged into the Raptor motor controller. The dash lives!

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The new instrument cluster is wired up, then
installed in the Jeep for use.

     As a last note, I did go ahead and install two green LEDs (tied through a resistor to their respective turn signals) for indication. I simply drilled two small holes in the MDF and hot-glued them in place. Now about the analog dash. It was working great, but now my 60-160volt voltmeter is dying. It appears to have developed a loose connection internally, as it often gives inaccurate readings unless I tap on it. I guess I'm really not too surprised about this, as from the beginning I suspected that these Westach brand gauges are (to be nice about it) not good products. Oh well, at least the ammeter (which is also Westach) seems to be working for now. Too bad the back lights in these Westach gauges are hopeless :( Note that the 9-17volt voltmeter I bought is made by Equus, and appears to be well made.

Clock & Power status:

     Cherokees have a big blank panel under the clock, which is conveniently located in the center dash area of the Jeep. Unfortunately, the clock's circuit board extends down into this blank space. However, I was able to use the blank bottom strip under the clock to place "power status" lamps. In order there are: A green lamp that indicates when the vehicle is on, An amber lamp to indicate when the solar system is charging the 12v battery, and a red lamp to indicate when the onboard charger is charging the 144v batteries.

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The new, modified clock module with "power status" indicator lamps!

Remember, More photos are in the Photo Gallery!