On the heater box you have to pull out the 2 white plugs that operate the fan relay and the vacuum hoses as well. Again, pretty simple..
Heater control box removed (nice and dusty in there)
At this point I just started to label everything! I just used a piece of masking take and a black sharpe marker and taped it up jut over the connectors. I knew if I didnít start know itíd be confusing later as thereíd be a lot of hanging wires.
Just labeled them like this
The indicator lights and instrument warning cluster was next for removal. Itís all wired using a flex circuit board and each running to a two separate connectors (the indicator lights have two connectors, each molded into the plastic bracket and there is one on each side of the steering column). Detach these connectors from their respective circuit boards. The wires on the drivers side of the harness will be used to splice the connectors onto the new gauges, accept for the right turn signal and seatbelt idiot light (I didnít use this light as thereís no indicator for it on the CJ
cluster) theyíre on the right side connector. I labeled it connectors and removed the piece.
Plastic idiot gauge housing
For the Speedo and Tach, itís aging just a matter of 2 screws on each to get them out. The tach will unplug and the Speedo cable wit snap out.
Tach housing Tach and speedo same mounting
Now everything should be fee of the dash frame.
The bare dash frame
So, now we can remove the steering wheel, tilt lever and automatic shifter (if youíre auto).
Remove the bolts that run along the top of the dash frame that would be beneath the windshield and on top of the cowling. Then the remaining torx on the sides of the dash frame and off comes the dash frame.
From here youíll be in amazement of the maze of wires that are now exposed! And you thought this was going to be easy?
Since the stock gauges are wired in the cluster using a flexible circuit board, each wire needed to be traced out to find it's respective color/gauge in the YJ the gauge cluster first (the Haynes manual also has an illustration of this to help trace out the wires. I double-checked it manually).
When wiring in the new gauges youíll have to do some splicing here to get the 12 volt power from there to the separate gauges outside of the new CJ cluster, which are the Volt meter and oil pressure gauges. I used the 12-volt power out of the YJ gauge harness and spliced in three to feeds, to supply the voltmeter, 12-volt to oil pressure gauge and then off to the fuel gauge on the CJ cluster. This was necessary because the old YJ cluster contained all 4 gauges with the same power feed.
The Tachometer Ė This is the part that was a pain and took many posts on JF and gaining the knowledge of both series and conventional tachometer wiring. The YJ has a conventional wiring style where as the CJ uses one thatís in series. Meaning thereís no ground. Hereís a good diagram of what I had to do to get it to work. I ended up having to cut the (+) wire just after the coil and resistor and spliced in the CJ tachometer. This was a struggle to trace down all the wires and because of the system if difficult to tone out the wire. I then used the OEM YJ plug for the instrument light (+) and (-). I left the OEM signal in case I ever wanted to switch it or run 2 tachs.
Speedometer Ė I had to install a new cable from the transfer case to the back of the CJ speedometer. The CJ speedometer uses a screw in type connector on the gauge whereas the YJ has a snap in type of adapter. There had to be a new hole drilled in the firewall because of where the new speedometer location is. I drilled in just on the inside of there where the gauge wire harness comes though almost in the middle, right behind the cylinder head.
The CJ cluster Fuel and Temp gauges were wired straight across the board but, know that the CJ uses a sender thatís totally opposite form the YJ. So I had to install a temp and fuel sender. If you donít the temp sender will be 40 degrees off and the fuel will read empty when full and vice versa.
On the Indicator lights I had to trace them as I did for the gauge cluster. I ended up just turning on the jeep making the light illuminate and bingo that was the light feed. Again trace the wire to the plug and there youíll find the wire you need. From there just cut and pasted them to their new location on the CJ cluster, it was pretty easy. There were only 5 of themÖ
Wiper Motor and Switch
I used the left the existing YJ wires in place seeing that they operated off the steering columns and I didnít want to screw with that at all. So I ran a 12v ignition supply to the CJ wiper switch and just used that to go straight to the wiper motor. The YJ has a 5 wires whereas as the CJ motor only has 4. The newer YJ motor uses a separate grounding wire.
The headlight switch was a straight across swap of wires between the YJ and CJ harness. I used the Haynes manual to cross-reference the feed wires.
Instrument Gauges Volt and Oil
The instrument gauges (volt, water temperature, oil pressure, fuel) were wired up using a 12-pin male/female connector in similar fashion to the indicator lights. The speedometer only required wiring up the bulb and the tachometer used the gauges existing wiring harness
Number 8 ring clamps were used for the terminal connections and the ring clamps/wires were crimped and soldered for extra strength.
With the gauges wired up and secured to the dash, it was time to install it into the Jeep. Maneuvering the dash into place over the steering column was a bit tricky, but it does fit.
With the dash over the steering column I secured the wires in a loom harness that I made and plugged in the gauges, lights, grounds, etc.. I attached and secured to the loom and wires to the back of the dash using black zip ties.
I then installed Rockford fosgate 5 1/4 ď speakers in the dash the headlight switch, dimmer switch and wiper switch were all done with the dash in place but not bolted to the jeep. (if I had to do it over again, I would have installed the speakers before the frame was slipped over the steering column, itís a pain to get you hand back there with all the wites).
Note : The cut-out for the dimmer switch was too small so a dremel tool was used to enlarge the opening a bit. This might have been caused by the added material from the plating shop though.
The last thing before tackling the Heating was running the new speedometer cable to the transfer case and to the back of the speedo. The YJ speedometer uses a snap in type connector and the CJ speedometer screws in. I purchase a 62Ē cable and it was perfect. I drilled a new hole in the firewall just below where the loom comes through to go the computer. IT was basically inline of where the back of the CJ female connector is. If I had to do it over again, I would have purchased a bit longer of a cable because it would have been easier for routing and attaching to the frame.
Heater and Vent
I already had matched the fan control wires with the CJ fan switch, which was very easy, Low, Med, and High, then thereís a ground and 12v source all taken from the YJ moduleÖ Pretty basic. However, you wonít get the fan to turn on until you attach the two white wires together that were mounted to the YJ heater control module. It the witch on the top far right of the box as your looking down on it. The switch basically turns off the power to the fan control if the lever is slid in the off position. Seeing that the CJ doesnít have a set-up like this I didnít worry about it always having power so, I just fused the wires together and bingo, the fan is blowing.
Hereís another shot of the fan control and you can see the module that Iím talking about on the upper right
I also just connected the YJ vacuum connectors together so when the engine is running the vacuum is always engaged. Again, I didnít see any harm in always having it actuated. If it fails in the future, Iíll just disconnect it and figure a work around. But as of not there hasnít been a problem.
I then got the CJ cables and mended them to the existing YJ cables going to the vent, defrost and temp controls, which are all controlled, by cable. In some places the indicator plate/light may be reversed as in push for heat and pull for vent. I thought that it was no big deal and left it. However, later Iíll reverse it with a cable reversal unit.
To get the defrost to work I just cut a long rectangle hole in the top of the dash frame almost where the YJ one is but a little higher and skinnier. When it was all mounted up without the dash pad on, I got the cutting tool on the dremel and make a slice along the top of the frame about a ľĒ wide to allow the air out at the top. The defrost is not as strong as it was with the large YJ hole but, it beats having a rusting windshield from venting it in the frame like the CJís. I also made a grove in the back of the CJ pad to allow the air to be angled up otherwise the pad would cover the hole I made.
I used small hose clamps to mend the vent cables together and a small stainless bolt to attached the cables together.
I then mounted the Dash Pad and covered the wiper linkage holes using some stock CJ covers. And attached the grab bar, glove box door and column cover in completing the install.
The new dash looks absolutely fantastic and the quality of the dash is excellent. The new dash is heavy duty and adds a "classic" touch to the Jeep.
If you plan on doing this swap, make sure you are very comfortable and familiar with electrical wiring diagrams can read schematics and know the basic principles behind circuits and such.