Written by Bob (rwenzing)
Radio removal tool (horseshoes)
7mm socket and ratchet
Soldering iron and solder (optional)
OEM Ford head unit with the SSV feature
Scotchlok wire tap
Short length of wire
Explorer 20-pin radio plug pigtail
or small individual pin w/shrink tubing
Some higher end Ford OE radios have a feature called Speed Sensitive Volume. This allows the head unit to increase radio volume automatically as vehicle speed increases (to help compensate for increased road and wind noise at higher speeds). I recently installed a 98 Explorer dual media with SSV. I have also heard that some of the Ranger 6-disc in-dash units have this feature.
To find out if your Ford radio is equipped with SSV, turn on the radio power by pressing the volume ****, release the ****, then press the volume **** again and hold it for 5 full seconds. If the display goes out on the second press of the volume ****, sorry, your head unit doesn't have the SSV feature.
But, if holding the **** for 5 seconds brings up the words "SPEED VOL" on the LED display, you have it! It can be adjusted for a volume correction of "0" (none) through "7" (max) using the same +/- control that adjusts the audio. Level "3" is a good first guess. You can tweak it in later to your liking.
So let's say that you have determined that your head unit is one of those that have the SSV feature. It still won't work because Rangers are not factory wired for Speed Sensitive Volume. But it is easy to add the wire.
Release the radio head unit from the bezel by using a set of the horseshoe-shaped tools designed for this purpose Ė these are available almost anywhere car audio supplies are sold. The discount store price is usually about $4.00. Slide the radio out until the rear connector becomes accessible. Unplug that 16-pin connector and the antenna lead to remove the head unit.
It will make access easier if the radio bezel is also removed. There are two bolts above the A/C control panel that can be removed with a 7mm socket. The bezel can then be pulled free from its retaining clips. Release all electrical connectors from the bezel including those for the lighter, the 12V power point, the foglamp switch (if equipped) and the 4x4 selector switch (if equipped).
The Gray/Black Vehicle Speed wire is accessible at the GEM module to the left of the radio cavity. This is where owners of 2003-back Rangers can tap the speed signal. This is the same wire that got tapped if you have done the Explorer/Mountaineer overhead console mod.
I tapped that Gray/Black wire and extended it to pin 9 of the 20-pin receptacle on the back of the head unit. Thatís all there is to this mod! I suppose that you could wire the Gray/Black wire to pin 9 using a very small female pin insulated with shrink tubing to isolate it from the other pins. I used a 20-pin Explorer plug connector and pigtail on mine because I already had it on hand. If you have a 1996~2001 Explorer pigtail, the color code for the SSV wire there is also Gray/Black.
Reassemble and enjoy your new mod.
This feature was easy to add and very useful. No more constant fiddling with the volume as you get on the freeway or stop for lights.
NOTE 1: If you have a 2004~2005 truck, the GEM has been replaced by the Smart Junction Box in the passenger side kick panel. You will need to pick up the Vehicle Speed pulse from a gray/black wire either at the Smart Junction Box or at the instrument cluster harness.
NOTE 2: Owners of Ford OEM 6-disc indash head units should pay particular attention to the orientation of the head unit when reinstalling it. These HUís are sensitive and should be plugged in to the power connector only when the unit is being held level.