Have a question? My 66 Monaco heat works great, but would change to defrost.

[Imp66]

Is it a vacuum system or is there another reason?

 

[CBODY67]

Under what engine vacuum conditions/levels?

The lever and cable vary the amount of heat. The pushbuttons direct the vacuum to open/closer the vac actuators for the ducting.

 

[Imp66]

383 heat is great but flow at defrost

 

[CBODY67]

Will the ducting actuators change as the buttons are pushed to different positions? A verified strong and stable vac supply to the switch?

 

[70NEWYORKER]

With the Heat button depressed is ALL the airflow directed on the windshield?
When switched from Heat to Defrost does the airflow become greater at the windshield or remain the same?
In normal operation on the Heat setting a small amount of air is bleed off towards the windshield to prevent fogging.

 

[Imp66]

Will the ducting actuators change as the buttons are pushed to different positions? A verified strong and stable vac supply to the switch?

No there is no change when defrost button in pressed

 

[Imp66]

With the Heat button depressed is ALL the airflow directed on the windshield?
When switched from Heat to Defrost does the airflow become greater at the windshield or remain the same?
In normal operation on the Heat setting a small amount of air is bleed off towards the windshield to prevent fogging.

Seems to be nothing going to windshield

 

[CBODY67]

Have you done diagnostics of the hvac airflow per the Factory Service Manual (free download) at www.myumopar.com ? Just curious . . . If there might not be a Dodge C-body manual, a Chrysler manual of the same model year can work as the C-body HVAC units all work the same

The amount of "bleed air" via the defroster vents when the HEAT button is pressed is not much. Probably the result of the flaps around the metal valve not fully sealing, but NOT like it only closes 90% of its total rotation, I suspect. On our '66 Newport, when the actuators stop moving, there is kind of a light "thunk" when they stop moving.

CBODY67

 

[Imp66]

Have you done diagnostics of the hvac airflow per the Factory Service Manual (free download) at www.myumopar.com ? Just curious . . . If there might not be a Dodge C-body manual, a Chrysler manual of the same model year can work as the C-body HVAC units all work the same

The amount of "bleed air" via the defroster vents when the HEAT button is pressed is not much. Probably the result of the flaps around the metal valve not fully sealing, but NOT like it only closes 90% of its total rotation, I suspect. On our '66 Newport, when the actuators stop moving, there is kind of a light "thunk" when they stop moving.

CBODY67

I will take look after our snow storm passes