Heater/AC Blower doesn't work

I have a 2000 SSEI and have had my heater blower replaced once already. This summer a new problem has shown up. My heater/AC blower works when it feels like it. I go over a bump sometimes and it starts to work. Sounds like a loose wire or connector. Any ideas? Do I have to remove my dash to trouble shoot the wiring for the AC/Heater blower fan? Last time I had it in the garage for a blower problem, I was $700 poorer. Any help would be appreciated!
Thanks.
Bob