Honda Repair: A/C Heater fan loses power, power transistor, control switches

Question
I bought a 2002 Honda Civic used in 2006.  It seems to have an ongoing fan problem.  The first summer I owned it the air conditioning was not working properly so they ended up taking the surround on the radio, etc. off to get at the air conditioning switch to turn it on.  This 'fixed' the air conditioning but now I have cold air blowing all the time unless I turn on the heat and turn the fan off and circulate the air internally.  Then I found that after driving for 20 to 40 minutes, the fan would start losing power so that even though there is heat or A/C the fan has no power.  After stopping for 10 minutes or so it will work again.  Last time the car was in (a week ago) after the fan totally died, they replaced the HVAC Fan Power Transistor (Resistor Module) and I thought the problem was solved.  No, it happened again on a longer drive.  I have checked the fan filter.  I have been told that they can only figure out what the problem is if I bring the car in while it is happening.  As it only happens on longer drives (usually the weekend)this is not a simple issue.  Any ideas on where to look, what to do next?  Thanks.

Answer
Johanna, sorry for the delay in response time to your question but, i have done a ton of research on this specific vehicle and model. I have come to a crossroads on my advice to you. Start replacing with brand new components. The reason being is that i think some time in this cars past there have been some repairs to this vehicles heater core and the fan/blower area. Possibly with a used unit and this could be causing the failure. The only other thing i could come up with would be to advise you to replace the entire climate control instrument panel. This can cause similar problems to what you are describing too. But the blower/fan unit is the less inexpensive option. Then move onto the climate control switches. Also you could have an obstruction within the door that allows the switch to open/close from recirculate/fresh air. Other than that there is really no other explanation for me to give you besides me ripping it apart and physically inspecting under the dash with my own eyes. I hope this helps u and let me know what happens...