99 avalon outside temp/blower motor prblm?

i have a 99 avalon xls with temp control it doesnt happen all the time but the outside temp gauge sometimes doesnt work it just says "outside temp" with no temp when it doesnt work the blower motor for the heat doesnt work its been taken to many dealerships and different shops and noone can figure out the problem does anyone have a similar problem can anyone help
thanks for any input and time to reply
Dave