This is the AC/heater control panel on my 1997 Jeep Wrangler. You may notice the knobs on the slide controls are missing.

I noticed the knobs were gone when I bought the Jeep, but I thought for sure there would be some place to buy cheap replacements…WRONG.

I searched all over ebay, aftermarket parts suppliers, junk yards, etc…nothing. Plenty of places to buy the whole control unit, but not just the knobs. The more I looked, the more frustrated I got, and the more determined I became to find a solution to the problem.

Step 1: The Idea

After realizing I wasn’t going to find an actual knob to fit this Jeep, I resolved to find some gadget to modify into a new knob. After a couple of failed ideas, I finally found a solution…tire valve stem caps. These are a fancier valve stem cap with an annodized aluminum outer shell, however they are easy to find at your local Wal-mart, etc.

As you can see in the close-up of the slider control, the knob will require a horizontal slot to slide onto the control arm, and then a vertical pin to hold the knob on…so that’s what we’ll create.

Step 2: Measure and Drill Hole in the Knobs

We begin by using a piece of paper and a punch to measure how far from the face of the panel the hole needs to be for the vertical pin.

Then, we transcribe this measurement to the knobs and drill a hole. Note: the hole in the knobs should be the same diameter as the hole in the slider. Drill all the way through the knob (i.e. through both sides)

Step 3: Cut a Horizontal Slot in the Knob

We now need to cut the horizontal slot to slide onto the control arm. For this I used a Dremel-type cutting wheel (as pictured). You could also use a hacksaw or coping saw, as long as you have something to hold the knob securely. Make sure to cut the slot perpendicular to the holes you previously drilled.

Step 4: Test Fit

We are now ready to dry-fit the knob on the panel. For the pin, I wanted something that had a head on it, so it couldn’t slide through the knob. I found a simple household tack that had the right diameter. If it fits nicely, slide it back and forth a few times, and give yourself an early pat on the back.

Step 5: Final Assembly

Final assembly. In my Jeep the knob needs to pivot slightly as the arm moves across, therefore I chose to use silicone glue, which will remain flexible when it dries, yet still hold the pin in position. After filling the cap with glue and assembling, I used some wire cutters to snip off the excess portion of the vertical pin…let the glue dry, and…you’re done!!

Step 6: Final Thoughts

Other options you may want to consider: The valve caps come in different colors (I’ve seen black, blue, red and chrome), so you can give your dash some "bling", if you want. Also, I thought of painting the head of the vertical pin black to hide it, but decided to leave it to serve as an indicator mark for the knob. If I were to paint it now, I’d paint it with some kind of glow-in-the-dark paint so you can see it at night. Also, if you don’t like the feel of the aluminum knob, you could dip them in plasti-kote prior to assembly.

Well, I hope this instructable provides you with some inspiration to make your own repair. While I’m happy with how the repair turned out…I’d love to use a 3D printer to make myself a new knob (hint, hint). Vote for me, please!