Rep Power: 0

2003 1.7 civic ex sedan

Heat was good till I fixed the AC. AC is always on now!

AC is always on now.

Very cold air comes out of vents instead of heat.

The Hot/Cold switch was working before. ill have to test it more.

The control valve before the heater core opens & closes the water way to the heater core.

Both Rad fans are always on. compressor must be always on too.

the heater & rad hoses are hot & pressurized.

its about 30 deg outside

I disconnected the AC pressure switch to turn off the compressor, now the air is a bit warm but not hot. ( i will test this more)

Help! where do I check now?

 
Rep Power: 518

That sure doesn't sound "fixed" to me!
Why can't you shut the AC off normally? What did you do to it?

The heater can always overpower the air conditioner. You can always have 'good' heat even if the AC is running.
If you have poor or no heat output, that's a problem by itself.


Does the water valve actually open and close the water passage?
BOTH heater hoses are screaming hot?
Operating temperature not high enough?
Air mix doors (linkage and servo) on the heater box move to the full heat position?

Does the heat output get warmer when you rev up the engine, then cool off after idling a for a couple minutes?

Is the radiator full of coolant? Air pockets burped?
What's the concentration of the coolant?


Head gasket......