Heating Fan dosent work on the first two settings

engine rad fan, AC front condensor fan.???
all have fuse
all have relays
we test those
and even hot wire fans to make sure fan even works.
or cab blower fan dead.
we can not guess fans, ever, learn to be specific, even tell
exactly where it is.
some cars have 4 fans, 1 cab and 3 up front, or just 1 huge one up front, and I and not guessing your country or engine so , I STOP

blower dosent work the fan dosent ????? 2005 pontiac what ???? The heater blower motor isn't blowing any air , What fan doesn't work ? Need better info .

cab heater? there are 3 fans, engine,cab heat and A/C. so....
a stuck CAB switch is a bad switch. easy huh?
if the switch only works on high but does move, that is a bad heater fan Resistor block. (usually bolted to fan hosing as it is air cooled this part)

try some comma's?
my wild guess, is you are trying to fix a dead cab heater, right?
and if so, can be caused by 5 things wrong. total.
1 engine coolant not hot (180F or more)
2; fan dead.(cab heater fan)
3:or core , coolant path blocked. (seems you)
4; core exterior core blocked with leaves or pin needles. (sucked in)
5: optional core valve , stuck closed. (cable bad, etc)\



one pipe hot , means ,? core pipe 1 is hot, and other is dead cold?
this flow blockage , bingo !

if pipe 1 is 180F and other is 120f this is normal the heater is heating air in the cab and is dropping due to this heat exchange. (normal)
so why not do the 2 year full flush service now. (skipped i bet)
core hoses:
remove the 2 hoses on engine side, never core side (easy damage)
then back flush both hoses. with a garden hose.
if there is a valve there, test it and make sure it's opening... and free flowing.
and that both engine water ports are open too, from heater hose
to engine. (yes, they pack up too)

check the regulator /resistor its the component thats plugged in and mounted at the fan / blower unit this link should help
Replace Blower Motor Resistor in 2004 Silverado

is this the blower motor fan for you heating and A/C or the cooling fan cooling fans have a relay blower fans are fused but controlled from switches inside as well as fuses

no, you may have two problems, the fan il bet is a blower motor resistor,replace that and fan will work again, the selector problem may just be bulbs not lighting, if you can can air to blow in areas you select then dont worry about the light not lighting, if it dosent select then replace the head, hope this is helpful.

resistor (or blower fan module) is bad

If the engine is not over heating then it is doing its job. The constant cycling is based on the temp of the air traveling through the radiator and the a/c condenser not the outside temp so much. The start up high rev is just how these clutches work in ford fans. It sounds like it is operating correctly.

You will need to replace the blower speed control, it is shorted.