Smashburn17

So after driving around 30 miles the evap freezes over not allowing air to pass thru. So I replaced the high pressure switch and the evap temp sensor. It didnt fix the problem so the next thing I looked at was I noticed the compressor wasnt cycling off. Forums said to replace the ac relay. So I did and still no help. After that it said to replace the head unit. So i ordered and new (used) one. When it arrived I went to install it and when I unplugged the old unit I noticed a wire was cut and another wire attached to it. So I looked at my wiring diagram and turns out the wire that was cut is for the ac signal (wire 11) so I traced it to another junction box under the ds dash. Which is where the diagram shows it to go. On a side note my ac button does not turn on. Only my Max ac button turns on. I installed the new unit but it didnt fix the problem either. I don't know what to do next. Thank you
edit: ac clutch always engaged

holmesnmanny

if the evap is freezing over then the expansion valve is bad, which is a common issue with this generation

what's supposed to happen is the evap temperature sensor is supposed to turn off the compressor when the evap starts to freeze just like it does on any other honda but for some strange reason on this particular generation that never happens

I've had this issue on both my 06 and 10 civics and the evap temp sensor system is a joke, the people that designed the ac system on this particular generation are morons

you need to put the wiring back the way it was and replace the expansion valve and evacuate the system and recharge to spec and you will be good to go

Smashburn17

Ok, but why does my normal ac not work? Just

holmesnmanny

either a wiring issue as you stated it had some stuff going on or the ac control unit is bad

either way, because the evap is freezing that means in theory the ac would work, if not for the freezing

holmesnmanny

this is how you pull the unit

Smashburn17

I replaced the expansion valve and condenser still freezes, what's next?

holmesnmanny

disconnect the evap temp sensor and see if the clutch still engages

also, see if the clutch is engaged with the ignition off

sumdewd

Do you mean the evaporator still freezes? Was the system properly evacuated and recharged by weight, or was this at home with walmart death cans attached to the single hose that said you were in the green?

You should always check the free and easiest stuff first after verifying a proper evacuation and charge by weight before replacing parts. ASSuming the wiring issue was fixed, freezing over in these MVAC TXV systems is usually either a bad evap sensor (or related wiring) or a compressor clutch staying engaged. NOTHING can command the clutch off if the clutch air gap is too small and it's engaged at all times from passive magnetism pulling the outer hub in from a tight air gap.

Try turning the outer compressor clutch hub by hand with the engine off. If you can move it around, the clutch might be within air gap spec. If not, you might need some shims in there to correct the issue. If the clutch is worn too much you may need a new clutch in its entirety.