Here is a write up that a member did a while back on adding cruse to a OBS truck.
Thanks to 94strokerace.
Ford F-Series 94.5-97 Cruise Control Mod
1. Cruise control equipped horn pad. This can be purchased new at Ford or eBay, or used at a junk yard.
2. (2) small spade connectors
3. A short length of #10 wire
4. A short length of shrink tubing
1. Needle nosed pliers
2. Side or diagonal cutters
3. A heat source (cigarette lighter)
4. Crimping tool
5. Soldering iron and solder (optional)
1. All brake lights must be operational including the third brake light.
2. The neutral safety switch must be operational (or start interlock switch for the manual tranny
folks) located on the clutch master cylinder shaft that penetrates the firewall))
This is a simple “how to” write up and basic overview based on my experience. The goal is to add the cruise control function to a truck that didn’t come so equipped from the factory. This mod will not require the installer to modify the trucks electrical system. As with any mod, after installation, and on the initial test drive, please test vehicle in a remote area for your and others safety.
<font color="blue"> 1. </font> With the ignition off, sitting in the driver’s seat with the steering wheel directly in front of you:
1.a. Find the seam of the horn pad, follow it down the steering column to its base.
1.b. Gently pull on the pad’s base directly towards you, this will not take a lot of effort.
1.c. Once the pad dislodges, carefully lift the pad tilting it to one side, exposing the connector.
1.d. Using needle nosed pliers, disconnect the small harness.
1.e. Once disconnected, the old horn pad can be set aside.
<font color="blue"> 2. </font> Installation is reverse of disassembly. On the back side of the horn pad you will see a pin, centerline. On the column, find the slot that the pin engages and:
2.a. With the small harness made up, slide the pad down, evenly, until the pad is flush with the
remaining steering wheel. Most likely the horn will sound by pushing on the pad.
<font color="blue"> 3. </font> Your almost done, move to the engine compartment and:
3.a. On the driver’s side, locate the Power Distribution Box.
3.b. Originating from the PDB is a two wire run w/ a connector. The connector will have a dummy plug installed. The two wires are black w/ a red tracer and brown w/ an orange tracer. The connector would, if equipped with factory cruise, connect to the brake master cylinder. This would be a redundant method of cutting off the cruise function if the primary function failed. Since your truck is not factory equipped with cruise, you master cylinder doesn’t have the switch, therefore the connector must be shorted. Do this by:
3.b.1. Remove the dummy plug
3.b.2. With a small, male spade connector, remove the crimping plastic insulator (this is because the insulators are too bulky to be placed side by side in a small connector)
3.b.3. Trim both sides of the spade equally using the side cutters. Test fit. Remember, two spades will be placed close together, trim accordingly.
3.b.4. Once satisfied with the fit of the spades in the connector, make up a short piece of #10 wire, crimp on the spades or solder if desired, and use the heat shrink in place of the plastic insulator removed in step 3.b.2.
3.b.5. Insert the shorting wire into the connector. It’s a good idea to drip some wax on the connections to weather proof. Liquid electrical tape would also surfice.
There is another method to short the two wire connector.
1. Cut off the connector, leaving a generous pig tail for future splicing.
2. Simply strip and connect the two wires together using a but connector.
I don’t recommend this because if you ever replace the brake master cylinder, purchase a replacement M/C with one fitted for cruise control, purchase the switch that would install in the M/C, remove the shorting wire and connect to the new switch. One step closer to factory!
As recommended, test in a remote area. Once desired speed is met, engage cruise. Test by tapping clutch pedal, ensure C/C disengages. Reset speed and test again by tapping the brake pedal. Once more by pushing the OFF button on the horn pad.