I am helping a friend with his low mile 81 (only 2000).. The red rear suspension warning light is on 80% of the time. I am not familiar with the air suspension as I have a 79 CBX. What should I look for, are there any common issues?
i had the exact same problem on my '81 i restored. i would fill the shock with air and check every so often and it was indeed holding pressure. the light would come on and off intermittently but mostly on. i removed the sending unit and when i did some rust colored fluid spilled out of it. i sprayed contact cleaner into the opening in the sender overnight then i dumped that and sprayed some WD40 into it over nite again. i then dumped the residual fluid out and re-installed and the problem went away. good luck!