I have been told my old trane unit has a contactor problem- the indoor fan runs but the outside unit comes on sometimes but not always- an a.c. guy came out and scraped the contactor a little and that seemed to help for a day or so and then it started acting erratic again, but not near as erratic as before he came- is there something I can do to prolong it's life- I know I am coming up on replacing the whole unit -23 years old- but am just trying to buy some time- also a freon leak in the inside coil- had freon put in a few weeks ago and it cools good when it's operating - just trying to buy a few more months. Thanks,
jayem

If it is a contactor problem, replace it. It is a very inexpensive repair. I don't understand why your ac guy did'nt replace it instead of scraping it.