Click image for more information
by Dave Gallegos (TJBoomer on JU)
With all the components complete and bumper reinstalled, it was now time to turn my attention to the wiring. I wanted to tap some power off a keyed on/off circuit inside the vehicle to operate a relay, that operated power from a battery keyed on/off source. That way I would not have to worry about the switch handling too much power and would also insure that if the switch was left on after shutting down the jeep, it wouldn�t drain the battery.
For this part you will need approximately 20 ft. of automotive 16 gage wire, 2 - wire tap connectors, 9 - female spade connectors, 1 - male spade connector, a lighted on/off switch, Radio Shack relay, a bullet connector, electrical tape, assorted screw drivers, pliers and sockets.
1. Remove the glove box.
2. Remove the #4 (Door SW Defeat 10A) fuse located at the bottom right corner of the fuse box. This is so we can leave the doors off/open while we work and not worry about running the battery down. See Figure 1.
3. Remove the long thin panel on top of the dash that is at the bottom of the windshield. Careful, don't break it. See Figure
4. Remove the ashtray. Then remove the 3 screws that hold the radio/ heat control bezel. 2 screws are at the top and one is behind the ashtray. See Figures 3 and 4.
5. Carefully remove the bezel by pulling
slightly up and back, towards you.
6. Remove the 4 screws holding the switch bezel to expose the wires. See Figure 5.
7. Locate the wires leading to the cigarette
lighter and disconnect them. One should be black (ground) and the other should
be light blue (switched on/off power).
8. Remove enough black insulation tape to allow easy access to the black and blue wires (approximately 2" worth).
9. Cut 2 - 4" lengths of automotive 16 gauge wire. (One red 4" length for hot and one black 4" length for ground.
10. Strip the two wire ends and crimp a female spade connector to the stripped ends of the red and black wires.
11. Place a wire tap connector on the blue wire and insert the 4" red wire into the connector and securely close the wire tap connector with a pair of pliers.
12. Do the same procedure described in step 11 to the vehicle black wire using the 4" black wire and wire tap connector.
13. Using electrical tape, dress the wires to desired perfection.
14. Remove the desired switch blank from the switch bezel and install your switch into position with the switch light at the top.
Some shaving of the switch may be required to get the switch installed properly. I preferred to shave the switch instead of my bezel incase I ever wanted to go back to stock or just change things later.
15. With what's left of the red automotive 16 gauge wire, dress the wire neatly to and through the fire wall on the drivers side.
I went through the rubber grommet just above the steering column.
16. Strip the red wire and crimp a female spade connector
to the end closest to the cigarette lighter.
17. Reconnect the original black and blue wires to the cigarette lighter.
Up to this point you should have 3 wires with spade connectors (2 - red and 1 - black) ready to hook up to the switch. The black wire provides the ground for the lighted portion of the switch and connects to the top switch spade connector. The two remaining red wires with female spade connectors are connected to the last two switch male spades. Don't worry, it doesn't matter which wire to which male spade on the switch. The switch just closes the circuit between the two red wires. See Figure 6.
Time to test your work. First, insure the red wire currently in the engine bay is not touching any metal. Turn your ignition key on and turn your switch on. The lighted portion of the switch should light up. Did it light up? Super. Now leave the switch on and check for current at the end of the red wire in the engine bay with a circuit tester or multi-meter. Got current? Sweet. Turn off the ignition key and the switch and put everything back together in reverse order including the fuse and glove box. Your completed switch should look something like this: See Figure 7.
In the engine bay, dress the long red wire to the passenger side inner fender. I used the existing wire bundle conduit along the top of the fire wall. I first threaded the wire to the passenger fender then inserted the wire into the conduit with the other vehicle wires for that stock look. Ok, is your wire dressed? Lookin' good.
Now select a spot and mount your relay just below the fuse/relay (Power Distribution Center PDC) box on the passenger inner fender. See Figure 8. I had two relays to mount so I fabricated a bracket to hold both relays to an existing OEM hole on the fender. See Figure 8
After mounting the relay, insure your red wire will reach this position with a few extra inches to spare and cut the red wire accordingly. Here is the wiring diagram from the back of the relay package (Radio Shack part #275-0226) that will be utilized to connect the wires to the relay. See Figure 9.
18. After the red wire is cut to the proper
length strip the end and crimp a female spade connector to the stripped end.
This wire will be the wire that operates the relay and is connected to
pin 86 on the relay. Refer to Figure 9 for relay wire connections.
19. Open the PDC fuse/relay box located on the passenger inner fender.
20. Turn on the ignition key.
21. With a circuit test light or multi-meter find an empty relay slot that turns off when the ignition key is turned off.
22. Cut a length of the red automotive 16 gauge wire to go from the selected empty relay slot to the mounted relay with a few inches to spare.
23. Strip the wire at one end and crimp a male spade connector to the end just stripped. With the ignition key off insert the spade into the available slot and dress the wire to the exterior of the box and close the box lid. See Figure 10.
24. Strip the other end of the
wire that comes from the PDC fuse/relay box and crimp a female spade connector
to the end. This wire will be the wire to operate the compressor and connects to pin 87 on the relay. Again, refer to Figure 9
for relay wire connections.
25. Cut approximately 2 feet of 16 gauge black wire and strip one end. Crimp a 5/16" round terminal to this end of the black wire.
26. Remove the rear PDC fuse/relay box mounting bolt and install the 5/16" terminaled black wire end to this bolt and securely re-install the bolt. Insure the bolt is tight to effect a good ground.
27. Cut the black wire to length to reach the relay with a few extra inches to spare. Strip this end of the black wire and crimp a female spade connector to the wire. This wire will be the ground to operate the relay switch and connects to pin 85 on the relay. Again, refer to Figure 9 for relay wire connections.
At this point, you should have one unused relay terminal. This terminal will be wired to the pressure switch on the air manifold module.
More York OBA