Help with heat & A/C

rixatrix247

Does anyone know what might be going on with my 2006 Honda Odyssey. The front cabin heater is not warming up unless the temp is set to hi (not the fans set to hi, the fans are working fine on all blowing pressure levels). The rear heater is blowing fine and gets warm/hot like it should. Also, the air conditioning doesn't work in either the front or the rear (Not sure if the heating and A/C are two different issues though?). Again, the fans blow fine in the front and rear, but the temp doesn't change except for the heating in the rear. I can set the temp to anywhere between Lo, 50's, 60's, 70's, 80's and it will all stay at the ambient outside temp mixed with the engine temp whether the A/C or the heater are on (again, except for the heater in the back and if I put the front on hi only). Last year I spent almost 1k getting the A/C fixed (something about a bad magnet, I think??) and I replaced the blower motor resistor in the front cabin then as well, and it worked fine all that summer. Then this summer, I tried to turn the A/C on and no cooling, just air blowing. I checked the front cabin filter and it was fine but didn't check the filter in the engine b/c the screws are rusted and I couldn't get them myself yet, but since the fans are blowing really well still, I don't think it's the filters anyway. And now that it's getting colder, I tried the heat today and this is happening with that now too, so help is appreciated! Thanks.

thecardoc3

Your description suggests that you have an automatic system. Only getting heat in the high position suggests that the system cannot see the cabin temperature accurately, in essence it thinks the cabin temperature is higher than it actually is. By setting the system to MAX Heat, the HVAC system ignores the actual cabin temperature and provides heat.

I would start by pulling codes and then going to live data to see what temperature is being reported and then progress from there.