Jeep CJ Digital Makeover
A few months back, we did an installation of a 6 gauge system in an ’86 Jeep CJ Scrambler. The package included a complete instrumentation system for displaying fuel, voltage, water, oil pressure, speedometer, and tachometer. The system also includes indicators for turn signal, high beam, check engine, parking brake, cruise control, 4x4 (when equipped), wait to start (when equipped), automatic transmission gear indicator(requires optional sending unit), not to mention several performance calculations which include: 0-60 MPH (0-100 KPH) timer, ¼ mile timer, ¼ mile speed display, high speed recall and high RPM recall.
You may think adding all of this additional functionality would make for a complex installation, but this is not the case; we decided to give you an overview of the system installation including an additional ambient temperature gauge, and a tire pressure gauge system to demonstrate how straightforward the installation process actually is.
One of the first things you should do is unpack the package, check the contents, and then disconnect the vehicle battery connections before proceeding. Once you have the battery disconnected you can start by determining the placement for the sending units. The system comes with a new oil pressure, water temperature, and speed signal generator that need to be installed. In addition to the standard 6 gauge system, we are installing an ambient air gauge and a tire pressure gauge monitoring system. The tire pressure system has remote sensors that are mounted on the wheels inside the tires so we had the tires removed at a local tire shop, mounted the sensors and had the tires remounted and balanced. This system will allow the owner the ability to monitor all 4 tire pressures and temperatures from inside the vehicle.
After taking a mental note of which gauges currently worked in the Jeep and which ones didn’t, we looked at installing the speed signal generator. This device takes a mechanical signal from the speedometer cable and transforms it into an electronic pulse the digital gauge system will recognize.
Next on the list is the oil pressure sending unit. This sender is installed in the same fashion as the water temp, and once again no sealant is required.
The next connection we’ll make under the hood is for the tachometer connection.
We located the tachometer connector at the distributor and made the connection using a female spade connector. The location you make for tach will vary depending on application.
Since this vehicle is getting an optional ambient air temperature gauge we need to run the wire with sender under the hood as well. This was easily accomplished by cable tying the sensor to an O.E.M. harness behind the grill area.
After this connection was made, we found a suitable location to take our wires into the vehicle and used cable ties to secure the wires to the existing wire loom.
This allowed us a central location for wire runs and kept the unit out of the path of water and other obstacles.
We temporarily set the control module aside and concentrated on locating the rest of the wire connections. Most of the remaining connections we needed were in the factory speedometer wiring harness. We used a digital multimeter and located the wires in the harness for left and right turn signals, high beam indicator, 4 wheel drive indicator, and fuel sending unit.
The system accepts input from several different styles of fuel sending units, such as GM, Ford, VDO, and Stewart Warner, and can also be programmed for a custom setting for other type of senders.
Next, we connected and ran a 12 volt accessory power wire from the fuse box, a ground wire from the steering column area, mounted two push button control switches for the system under the dash, and ran all the wires to the control module mounting location area.