[1990civicdxhb]

ok,
1st of all,
everything you done above,is not gonna make your heater blow hot air,
I've took are heaters apart!
(completely)
inside the blower theres a little metal wire(sort of like a jumper wire)
sticking out,
when the blower motor is turned on,manually it just turns like a fan,
but if you plug in a plug thats under there(i think its clear or blue)
(under the glove compartment)
it turns red hot!
& thats how hot air is formed in a 4th gen civic!
make shore thats plugged in & there are NO fuses that is blowed,
because there are fuses to the heater blower,
good luck