This How To will walk you through the process of re-wiring the Cruise Control "On/Off" button on your steering wheel to control the volume"up/down" on your stock Mach460 headunit. I did this to my 99 mustang with the Mach460 headunit. Wire colors and stereo headunits may differ with different mustang years. I will also show you how to wire up a toggle switchso that you can still use your cruise control whenever you want. Their is some soldering involved, and if done incorrectly you could ruin your headunit, so be careful.
First you need a 3-wire toggle switch (9-pins on back). I was only able to find a 4-wire switch (12-pins on back) but that just means one row (3-pins) wont be used. an "On-On" switch is preferred, but an "On-Off-On" would also work the same way. I picked this 4-wire On-On toggle switch at Fry's Electronics for about $6.
Before anything, unplug the battery. Next you'll need to remove some panels to get access to the wires. The large panel below the steering wheel is held on by 3 clips at the top and 2 BLACK bolts on the bottom. Remove the two bolts and with a strong yank, the clips should pop out.
Now remove the metal plate behind the dash piece by removing the 2 SILVER bolts on either side.
Remove the piece below and behind the steering wheel by removing the 4 philips head screws as indicated in the picture
Remove the tilt wheel lever by unscrewing it counter-clockwise. Once off, pull down on the piece pictured above and it should pop right off.
Now you have easy access to the wires. Find the yellow wire insulation tube. Slice it open and pull out the Blue, Purple, and Black wire (all the same size) be sure not to mistake the thick black wire for the thin one. The thin one is the one we need. Cut these 3 wires about half way as shown in the picture below. The wires on the right lead to the buttons on the steering wheel and are labeled B1, B2, and B3. The wires on the left lead to the cruise control unit and are labeled C1, C2, C3. The labeling will be needed later when making your connections to the toggle switch.
Leave the above wires alone for now. We will get back to them later. Lets deal with the headunit now.
Removing the headunit is a little tricky if you've never done it before. Their is a special tool for this, but a coat hanger will do the job just fine. Cut a coat hanger into two 1 foot wires and bend each wire so that it makes a U shape. stick each end of the U wire into the square holes on either side of the headunit. Insert them about 3/4 of an inch in. push the coat hanger wires away from the headunit to depress the holding springs and pull the headunit out.
Once out, remove the black faceplate of the headunit by removing the torn screws on either side. Detach the wire plug behind the faceplate so that it's free from the rest of the headunit. With the faceplate off, remove all the small screws on the back which hold the green circuit board onto the black faceplate
Make careful note of the 3 points you need to solder wires to. I don't know any better way of showing the points then in the picture bellow. Once again, the labeling will be important when it comes time to wire up the toggle switch.
Here it is after the 3 wires are soldered on. Make sure these wires are long enough to extend out the back of the headunit
Once you've soldered the 3 wires in place, put the faceplate back together. The top of the headunit just pops right off. With it off, lay the wires neatly inside the headunit and feed them out the back. Then put the entire headunit back together
Now take these 3 wires coming from the radio (R1, R2, R3) along with the 3 wires behind the dash coming from the button on the steering wheel (B1, B2, B3) along with the 3 wires coming from the cruise control unit (C1, C2, C3) and extend all 9 wires to reach where you want the toggle switch mounted and wire up to the toggle switch as shown below.
This can get tricky if you have a small toggle switch like mine, buy take your time and make sure none of the wires touch.
Find a spot out of the way to mount the toggle switch and drill your hole. I chose at the very end of the dash panel directly below the steering wheel.
Put everything back together and mount the switch and your done.
