Bom's Evo

iTrader: (14)

Hello,

Just noticed no heat coming out of my vents. Air comes out at full power, but its cold air. A/C works perfectly and the fan comes on. When I change the temperature it stays cold.

I just topped off the coolant and made sure no air bubbles in the system this morning. Still no good. I just read about the Heater Control Transistor and the Blower Motor might need replacing.

Question is since it blows air, do I just change the heater control transistor "blower resistor" or do I have to change both?

Thanks for the help.

Veronica

iTrader: (2)

No. This indicates that the flapper door on the air box is not moving. Try the heat control transistor first.

The blower motor works - it blows air 'at full power', eh?

stfuad

heater core could be plugged as well

Veronica

iTrader: (2)

^not as likely. The heat would have been a gradual less and less over time...

Quick check is to feel the heater hoses going in/coming out of the firewall. Are both 'hot'?

These cars are low mileage and unless OP put 'stop leak' in radiator....

Bom's Evo

iTrader: (14)

Just waiting for the new heat controller transistor now I ordered it for 50 bucks.
I don't use stop leak cause no leak just Prestone 50/50 after my evo x swap.

Veronica

iTrader: (2)

I think you found the bad part. Please consider doing a write-up on remove/replace.

Bom's Evo

iTrader: (14)

I installed the new Heater Control Transistor.
This was not the issue. The new transistor, my fan would not even turn on at all AC/Heat.
I switched back to the old transistor and that got my AC and Fan working again. However, I still have no heat. Checked all the fuses and already did the coolant and thats all good.

Looks like the fan needs to be replaced since I read that theres also a fuse within that......