Take it to a mechanic.
i JUST GOT A QUOTE FROM THE DEALER FOR A 2002 ECLIPSE SPYDER - REPLACE THE HEATER CORE = $950 PLUS TAX go to regular mechinic core is around 30. to a 100. dollars
It is in the fire wall behind the heater box.
There isn't a block heater, unless the previous owner installed one.
Get a manual on your car and do the job correctly.
Behind A/C and heater control panel, in center console.
It's part of the heater core assembly so it's behind your glove box
The heater core is located behind the dash inside the heater core box with two ports, an inlet and an outlet port protruding through the firewall into the engine compartment.
Although my car is not an Eclipse, I experienced the same issue. A mechanic determined that my radiator was partially blocked and recommended replacement. My heater now blows heat whether I'm stopped at a light or moving.
your heater will be cold, or your engine can over heat. your car can take a long time to heat up. Your inside heater will be cool, or your engine temp. will over heat.
You need to remove the dash panel. It will allow you to get access to many connectors and it will be easier to remove the harness.
Trouble code P0135 means:O2 sensor heater circuit malfunction (Bank 1 Sensor 1)