Broken tach/"hopping" needle - cluster swap question

[stateofidleness]

Awesome, thanks Kevin! Found a couple good writeups on the EEPROM reprogramming part. I have a programmer and software to do that (I hope - a perk of being a software developer lol).

Was hoping for a bit more of a plug and play swap, but I think this is manageable if all goes smoothly and I get my LCD screen fixed AND gauge fixed all in one go!

[Gilles]

When I replaced the face gauges on my Cayman and pushed the needles too far into their shaft, therefore the tach needle was acting the way you described, a repair shop told me to install the needle at the bottom of the scale (0..) and "push it Not all the way in" so does not drag against the face cluster, you may want to give it a try..

PS: push the needle all the way in, then pull it up a couple of mm

[stateofidleness]

I did try that at first, at various "heights" off the face, but no luck. I found that the "stops" full counter-clockwise and full clockwise seem to be WAY off from 0 and 100%. when I rotate the needle by hand until I get to a "stop", it's like in the middle of the range. super weird... sorta feels like a gear or something is off or a worm gear type thing is broken (since it won't "go down" when running, only increases until it dimes itself and then won't move anymore).

[KevinH1990]

Originally Posted by stateofidleness

Awesome, thanks Kevin! Found a couple good writeups on the EEPROM reprogramming part. I have a programmer and software to do that (I hope - a perk of being a software developer lol).

Was hoping for a bit more of a plug and play swap, but I think this is manageable if all goes smoothly and I get my LCD screen fixed AND gauge fixed all in one go!

I had not programmed an EPROM prior to starting my gauge swap. I was fortunate that another board member graciously offered to guide me through the process. If you have prior experience with EPROMts, you are in much better shape than I was and you should be able to handle this.

I wrote a detailed document that contains everything I learned during my project. The file size exceeds the limit for attachments on this forum.. If you want a copy, please send me a PM with your email address and I will forward the document to you.

While you are planning the work, I recommend that you consider installing a 996 cluster if you can find an affordable used one, After using my car with the Carrera 5-gauge cluster, the 3-gauge cluster in the 986 looks like Porsche went overboard cutting costs on the 986.