Stevieporsche

i have owned a 90 944s2 cab for almost 3 years now. Before that an 89 944 for 10 years. My 944 S2 cab recently started doing this. While driving i push the snow button to turn on ac. Fan switch inside set to any of 1 2 3 or 4 blowing normally. Suddenly the interior fan stops and the speedometer drops straight to zero. If i turn the snow button back off and thus ac off. Speedometer comes back to life and works normally fan may or may not start blowing. This has been past few days now.

Sometimes ac and speedo work fine as they always have. Other times it is immediate reaction. Ac goes off. Blower fan goes off and speedo drops to zero mph. All the while nothing else happens and car continues to drive along with full power.

Nothing like this has ever happened to my otherwise perfectly working 944 in the past so I am stumped. How are speedometer and fan switch connected??? Where to begin looking?

mro763

I would start with the relays first. Change any relays associated with the a/c. It sounds like its electrical, maybe a loose ground? Good luck.

jhowell371

+1 grounds. There are many posts on the location of and cleaning grounds. The only electrical thing your affected components share is the ground.

Stevieporsche

I unscrewed and pulled the center ac switch mechanism out as far as I could without breaking or snapping the 25 year old parts and blew around the back of it with compressed air. Put it all back and so far no issues for a couple months now. Fingers crossed.