No heat

[jazziesdad]

Have no heat in my 2000 Ls V6, checked around and discovered a self test, did it and recieved the following codes 12 65 and 50 41, I found the 5041 was network communication error and 1265 refers to a malfunction in the cold air bypass door circuit, where do I begin?

[danielsatur]

AF > Lincoln >LS, Search ''No Heat'

[matthew24u]

Sounds like a blend door problem if you remove the LH floor duct you can get to the motor. unbolt it with key on try to switch from cold to hot if it doesn`t move test wiring for power and control signal if they are present but no movement replace blend door actuator. oops also make sure you have good ground. signed, always stuck in diagnostics!!!

[joegr]

You need to clear the stored codes and then rerun the test a few times. It is not unusual to see those codes with no real problem.

If, the 1265 (gen I only) keeps coming back, then your problem is that the cold air bypass door is stuck in the cold position. You have too choices then. You can fix the problem and get the door working again, or you can manually move it to the hot position and let it stay there. If you do the latter, the climate control will still heat and cool just fine. The gen II are setup without a bypass door, so they are always in the hot position. (In either case, the DCCV regulates temperature, not the air door.)

If 1265 goes away, then you probably have one of two problems. Either your DCCV is stuck closed on both sides, or you have air trapped in the cooling system.

If you just bought this LS and the heat never worked since you bought it, the previous owner may have plugged the heater hoses instead of replacing a bad DCCV.

[joegr]

Originally Posted by matthew24u

Sounds like a blend door problem if you remove the LH floor duct you can get to the motor. unbolt it with key on try to switch from cold to hot if it doesn`t move test wiring for power and control signal if they are present but no movement replace blend door actuator. oops also make sure you have good ground. signed, always stuck in diagnostics!!!

Just a correction. The LS does not have a blend air door. Temperature is controlled by the DCCV which controls the amount of engine coolant flowing through the two heater cores. The Gen I does have a bypass door to give slightly quicker cooling in the summer time. It is always either at full bypass or no bypass. It does not control blending of hot and cold air like a blend air door on most other Ford/Lincoln/Mercury cars.