[ghlkal]

I purchased a Tech 1 off eBay, but it doesn’t work.

It won’t read data from either my 90 or 85. Both cars will go into diagnostic mode by connecting pins A and B on the ALDL, and I can read codes on both cars using my cheapo code reader. When I performed a self-test on the Tech 1, it passed every test except [f7] which produced “High Speed Diff. Serial Data Test Fault.”

Does anyone know if it’s possible that just the cable (Tech 1 to ALDL) is bad, or is it likely the Tech 1 itself is bad.

Of course, I will “return” it if it can’t be fixed. But, if I can find a cable, I might try that too.

Thanks