I have been working on getting the A/C working in my 1972 Cutlass Supreme, the system is charged with r12 and operating. My only problem is that at times the compressor will not turn on unless I move the control lever back and forth from vent to the A/C positions. Can this switch be cleaned or adjusted, when it works everything operates as it should. Any help would be greatly appreciated.
When the compressor does not turn on, I have traced that there is no power from the connection in the A/C control.
Thanks

 

After years of use, the contact points can develop a varnish like coating on them. It only takes a light cleaning to remove that coating and restore them. If you are handy, you can take the control out of the dash and clean the point contacts. Use a VERY fine sanding paper or cloth. 1500~2000 grit or finer.

If you can reach it in the dash, you can slip the sand paper between the points and clean them in place.