Skip to main content

My carb was stuck on a Sunday start up so i I did my air cleaner to tap the carb to open and my air cleaner top slipped out of my hand and hit the ADP/speedometer wire. My speedo did not work after that.....any suggestions? Should I look to replace the speedo cable or the ADP? Could the shock have cracked something inside? Thanks in advance

Original Post

Replies sorted oldest to newest

Can’t fix what is broken until you do some more troubleshooting. I would start by disconnecting the speedometer cable from the right angle adapter. This should allow you to check to see if the output of the adapter is rotating, may reveal the tip of the cable drive shaft was broken by the lid - methinks that is not likely.

if the adapter spins and everything looks OK visually, you want to spin the cable driveshaft fast enough to see if the speedometer will react.

as for the electronic speedometers I know they are out there but I am still old-school. Someone else will have to chime in but just about all the major gauge companies now offer electronic GPS options


Dave C, the '90-'94 Pantera Si did in fact use an electronic version of our old mechanical speedo. Not sure, but I think the same ADP drive had a 2 wire electronic adapter screwed on where the cable drive goes. Then the wires terminated at the speedometer into another small electronic gizmo. But I wonder how that expensive bolt-on system gravitated onto an early Pantera? I passed up one from the Si crash test car 20 years ago because I couldn't afford it.

If an electronic sender is indeed broken, I cannot help. Perhaps Jon Haas could. He would probably need the sender on the speedo end for comparison.  But if your system is entirely mechanical as was stock, I've repaired a dozen of those. Look closely at whats on the ZF and take some photos, please.

Converting your mechanical speedo to electronic operation isn’t too hard. Any gauge shop can install electronic workings into your speedo. Then, you can drive it via a GPS sending unit or a VSS that mounts on the ZF in place of the angle drive. Another way to accomplish the same thing is to use SpeedHut’s electronic conversion box. It’s no cheaper than other methods but it leaves your speedo unmodified.

Add Reply

Link copied to your clipboard.