I have a 2001 Ford Focus DOHC. Heater doesn't blow hot. Hot cold indicator switch clicks as i9t should when I turn indicator but it doesn't seem to change anything

May have something stuck in your fresh air damper. Leaves, a cat...

if your heater fan blows all the time when you turn the switch on, then check the heater control valve under the hood right before the heater core. its inline with your heater hoses going into the heater core. the valve opens one way and closes the other way as you turn the switch from hot to cold.

HEATER NOT BLOWING COLD,NO HOT AIR FROM HEATER,A/C BLOWS HOT AIR,A/C NOT BLOWING COLD, COLD AIR FROM HEATER,BLEND DOOR ACUTATOR CLOSED,HVAC UNIT NOT OPERATING,
http://alltypesofpartsreplacing.blogspot.com/2012/12/heater-not-blowing-coldno-hot-air-from.html

Hi Tamara,

Please review the following article to get an idea of what could be wrong with your heater.

Why Is My Heater Cold?

Sounds like whoever did the repair work did not install the solenoid correctly or did not reassemble everything properly. If you had heat prior to the repair, the heater control panel must have been working. The mechanic must make a better diagnosis than this.

That part of the needs to come apart to see what is wrong.

does your blower motor work or it just blowing cold air?
if it does not blow then check the fuse, the motor may be bad
if it blows cold air only then check your coolant level
check to see if the heater hoses are hot on both of them
if the hoses are hot then you may have a blend door actuator bad

Check the temp dial, the potentiometer may be faulty

It sounds very much like the idle air valve is faulty as I have just had same sort of problem I fitted a new idle air valve and it has cured mine. Unfortunately these idle air valves are not cheap. They are about £70 from ford but you can get them on ebay for about £30 from partsdome

You need to replace the temp actuator.