2002 4.6is Please Help!!

[x5Alpine]

so I posted this before but now I'm going to do an update. My 02 4.6is has had serious issues with the heater not working as in the heater will work for about 5 minutes but then the display and heater together will flicker off and on. My indy and I have replaced the HVAC control unit 3 times, FSR, tries unplugging ambient temp sensor, nothing has worked!. AC works just fine but the second I crank up the temp and roll the dial on the vents to red it starts giving me issues. Please anyone help!

Thanks!!

[Omerta]

Have you tested all the relays in the system?

[x5Alpine]

The thing is is that it works fine sometimes when it seems like when the ambient
Temp is in the 40s to 50s.

[Omerta]

ok, spell out the entire problem.. sequence of events.. what you did in attempts to fix it and how it behaves under various conditons and functions. Your first post is very vague and hard to make any suggestions of what part of the system to look at.

[x5Alpine]

So it'll be in the 30's and I'll hit either the auto button or the face vent button. After about 5-10 min of driving the whole display and the heater fan will flicker off and on. My Indy and I have replaced the HVAC control module 3 times, FSR, and unplugged the ambient temp sensor. When the dial on the dash is turned to the blue everything works just fine.