Replacing Jeep CJ-7 Instrumentation Gauges

Jan. 18, 2011 By Jim Brightly
The new VDO gauges monitor all the engine’s functions, which allows me to take on some more difficult trails.

VDO is a leading international supplier of automotive and marine electronics and mechatronics - so says VDO’s website, and I believe it. Many of the high-end European automobile manufacturers happily use VDO gauges as their OEM instrumentation—albeit without VDO’s brand on the gauges.

First step was to determine how much space was needed for the new gauges.

VDO offers gauge designs that run the gamut of retro to futuristic and classic to modern. From VDO’s catalog I picked a design called “Vision Chrome.” To me, Vision Chrome offered the classic white-on-black lettering that I remembered from the street rods and custom Jeeps of my youth. It also had the six-gauge kit I was looking for.

Next, I needed to determine the amount of space available.

According to VDO’s literature, “Vision Chrome features crisp black dials and polished chrome bezels. High contrast clear white graphics and red pointers make Vision instruments easy to read. VDO patented movements provide smooth and accurate performance and long life dependability.”

The unused radio mount was the first thing to go.

My 1982 Jeep CJ-7’s OEM gauges were not aging well. They were fading and failing; the gas gauge’s needle, in fact, only traveled from between quarter tank and slightly above three-quarters. The engine temperature gauge, also located in the large speedometer cluster, didn’t give any numbers – just a green line for an operating range.

Then the voltmeter and oil pressure gauges were removed.

The optional voltmeter and oil pressure gauges worked OK, although they were getting a bit long in the tooth and I wasn’t sure how accurate they’d become. Added into the mix was the fact that when I installed the Chevy 400 small block V8 and Turbo-hydro 350 transmission, and I also installed 4.56:1 differential gears and 35-inch Goodyear MT/R tires. Since lower gears and taller tires play havoc with the speedometer and odometer readings—in this case, producing an error somewhere between 15 and 20%—I thought it was time to upgrade the Jeep’s instrumentation with new gauges and a programmable speedometer.

The large center speedometer cluster was the final gauge to be removed.

VDO’s Vision Chrome speedometer is electronic, so it’s very simple to program. Following the kit’s instructions, I stopped the Jeep at a highway mile post. I pushed the proper button to turn on its program, drove slowly to the next mile post, stopped, and pushed the button again. Now the speedometer indicated correct speeds and proper mileage.

After carefully measuring the space needed for the new gauges, the dash was cut out.

While the dash was being cut, we installed the temperature sender (which came with the kit).

Buried in the spaghetti of cables, wires, and hoses is the oil pressure sender.

Above the exhaust muffler on the rear housing of the transfer case, the speedometer’s sensor is installed.

VDO includes a wire loom with the kit.

Now comes the fun part! Once the panel is cut from aluminum stock, the holes for the gauges must be drilled out.

Once the holes are drilled out, they—and the panel’s edges—must be dressed and smoothed. All the necessary hole sizes are given in the kit’s instructions.

Time to make sure the panel will fit into its hole in the dash. Paul Schupp of Precision Automotive in Kingman, Arizona, is also marking the locations of the mounting bolts.

One final check — measure three times and cut once — before finishing up the panel.

This is the back of the panel. VDO had prewired the loom, but our gauge configuration did not match VDO’s, so we had to extend some of the wires. (This was a prototype wire loom, so production models will have more flexibility.)

Here’s the new VDO Vision Chrome gauge panel with the more important oil pressure and temperature gauges (with numbers) next to the driver, and the somewhat less important gas gauge (fully functional) and voltmeter on the far side. I also now have the speedometer and tachometer right next to each other.

The old gauges are now in storage in case a club member or my son’s Scrambler should need replacements.

VDO Gauges,
Precision Automotive, Kingman, Arizona Newsletter
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