tach not working
 

I have searched and found a couple threads on this. but never any solutions.

86 944 turbo. when I got this project running, the TACH did not work.

swapped a known good tach from another cluster that had a bad speedo. still not working. so suspecting the cluster ribbon cables.

swapped cluster and still the new cluster's tach does not work.

car starts right up and runs great. during rebuild and initially getting running, swapped both sensors and even verified clean signals to the DME. probblem turned out to be a bad coil.

so I am now suspecting something in the wiring from the DME to the cluster. also looked at Clark's garage and did not find any TACH troubleshooting guide.

thoughts and suggestions?

PS. just got it back up on jack stands to replace the clutch. installing a SPEC stage III and alum fly wheel.

The coil gets the same signal that the tach does, if the wiring is correct. Since your coil is working and the engine runs, check your wiring to the tach.

does anyone have the details of what to check? what pin(s) from the DME wiring to what pin(s) on the TAC connections?

This post from another forum has all the information you need...

Bench testing gauge cluster...mostly tachometer - Rennlist Discussion Forums

thanks for that link. looks like exactly the info I needed.

now have the 951 back up on jack stands to install a new SPEC stage III clutch pack and light weight alum flywheel.

will now include chasing the tach issue.