My speedometer stopped and the check engine light came on. I did the diagnostic and code 24 comes up. I switched out the speedometer, as well as the Vss buffer behind the speedo, but still no change. The cable is plugged in and appears to be doing its job. Does anyone have an idea of what I should check next?

I have a 1989 convertible Iroc (305tpi w/5speed)

 

What do you mean by no change? You mean the speedometer still doesn't work?

And, what do you mean by the cable appears to do it's job. Try jacking the back of the car up and driving the wheels. Is the cable turning?

You could have a broken cable, or stripped speedo gears in the tranny, or 2 bum speedos. Pretty much has to be one of those...

 

Ed, thanks for the reply. By "no change", I mean that the speedo still doesn't work. The service engine light comes on after driving the car about 2-3 minutes. I will do as you suggested and post the results.

 

Upon further review, it turned out to be the speedo cable. I was broken at thr transmission gear. Thank you for your ideas Ed.