Hello gentlemen, I need some help please. Just bought an 84 928s,5spd. Has some bugs. My tach, speedo , gas gauge, oil pres gauge are out. I hope it is all related to a single problem like relay , ground wire ,fuse etc. Air comes on for 5-10 secs and then cuts out. I suspect low freon. Will have it converted to R12 tommorow. Any advice will be greatly appreciated. Thank you .

 

Have you checked your fuses? In particular Fuse #12. https://www.928gt.com/t-8384fuse.aspx

Could also be a bad ground or even the printed circuit on the back which I believe is NLA.

AC is likely low freon. If you need a write up to track this down, read this... https://www.928gt.com/t-wallyhvac.aspx

All courtesy of 928 Specialists!

 

Thanks Andrew, I will try those things . If it turns out to be circut board ,then what ?

 

... Fass... Also, on the back of the instrument cluster are 3 connectors.
A crucial ground goes through the middle one. Be sure it, and all, are
firmly installed.


G'luck.

 

Fass...
bump... so, what's the verdict?


G'luck