1998 Honda Accord 4 cyl. heater blowing cold air

@acura "op hose is hot, bottom hose is Not" means the antifreeze is not flowing through. This can be caused by :

• clogged heater valve
• faulty air mix door
• heater valve cable adjustment

Here is the part of the SM that deals with the HVAC of your vehicle model. Check your heating system accordingly 98 02 Accord HVAC

Here is the test for the mode control motor

NOTE: Before testing the motor, check for HVAC DTCs (see page 21-101).

1. Disconnect the 7P connector from the mode control motor.

Incorrectly applying power and ground to the mode control motor will damage it Follow the instructions carefully.

2. Connect battery power to terminal No. 1 of the mode control motor, and ground terminal No. 2;the mode control motor should run, and stop at Defrost. If it doesn't, reverse the connections; the mode control motor should run, and stop at Vent When the mode control motor stops running, disconnect battery power immediately.

MODE CONTROL MOTOR

I3. If the mode control motor did not run in step 2, remove it, then check the mode control linkage and door for smooth movement.

• If the linkage and door move smoothly, replace the mode control motor (see page 21-62).
• If the linkage or door sticks or binds, repair them as needed.
• If the mode control motor runs smoothly, go to step 4.

4. Measure the resistance between terminals No. 5 and No. 7 of the mode control motor. It should be between 4.2 and 7.8 kO.

5. Reconnect the mode control motor 7P connector, then turn the ignition switch to ON (II).

6. Using the backprobe set, measure the voltage between terminals No. 3 and No. 7 of the 7P connector.

Vent: About 0.5 V

Defrost: About 4.5 V

7. If either the resistance or the voltage readings are not as specified, replace the mode control motor (see page 21-62).

f you find you have no power going to it, check the #56 in the fuse box inder the hood and check #3 and #13 in the fuse box under the dash.