Fan comes on shows temp but no heat

SOURCE: no heat

I had the same problem. It turned out that the small gray plastic lever arm that opens the mixer door was broken. The big problem with this is that to access this arm and mixer door, you have to remove the dash. You can feel and see the lever by dropping the glove compartment all the way and reaching to the front and left. It was a pain to replace, but well worth it.....

SOURCE: no heat

No Blower in Floor Mode
A customer arrives with a 1983 to 1995 Full Size Ford, Lincoln, or Mercury
automobile with automatic temperature control. If the complaint is no blower operation when
the floor mode is selected, the vehicle may have a problem with the thermal blower lockout
switch also referred to as the CELO (cold engine lock out switch).
The thermal blower lock out switch is located in the heater core intake hose. The two
wire switch has a thermal element with a small set of contacts, the contacts are open when the
coolant is below 120°F and closed when the coolant is above 120°F. The thermal blower lock
out switch also contains a vacuum switch, which applies vacuum to the outside/recirculate
valve when the system is in the floor position. When the engine coolant is below 120 degrees
and the selector is set to floor position, the thermal blower lock out prevents blower from
turning on and closes off the outside air during engine warm-up. When the coolant
temperature is above 120 degrees, and the selector is set to the floor position, the thermal
blower lock out switch allows the blower to operate and opens the outside air door.
In order to diagnose this problem, test the thermal blower lockout switch with the
engine at normal operating temperature (above 120°F). Unplug the wire harness connector
from the thermal blower lockout switch. Using a 15-amp fused wire, jumper the harness
terminals to test the switch. If the blower comes on, the thermal blower lock out switch is
faulty. If the blower doesn’t come on, look for an open between the control head selector and
thermal blower lock out switch.
In some cases the blower may continually run even when the engine temperature is
below 120 degrees. Unplug the thermal blower lock out switch and if the blower motor turns
off, the thermal blower lock out switch is faulty. If the motor continues to run, look for a
short to power between the control head selector and thermal blower lock out switch

SOURCE: both hoses to heater core are hot, blender door

if the air is definatly being blown through the heater core , then the core is blocked.if there is no hot coolant passing through the core then ------no warm air ---give it a good look see if you can see the deflector guiding the blown air is going far enough to send majority of air through heater good luck

SOURCE: 1994 lincoln town car, almost no heat, blend door

I had the same problem no heat or very little heat. my garage found the problem to be up under the dash something to do with the heatting door stock open try checking under the dash.

Jeffrey Turcotte

• 8991 Answers
• Posted on Nov 07, 2010

SOURCE: 1998 lincoln Navigator --- 1. NOT

It can be the heater core but can also be the water control valve or the blend door actuator.

Please see my tip at http://www.fixya.com/cars/r6235876-no_heat_fan_blowing_cold_air . These are generic instructions. If you get stuck or need specific instructions for your car, please get back to me with model, year and engine info.

First make sure your heater control valve on the heater hose is actuating properly when you change the temperature. The valve looks like the picture below.

If this is working, check the temperature actuator under the dash. If you system is cable operated, the cable sheath may have slipped the clamp. Make sure the door opens and closes all the way wheh the control is switched from hot to cold. If you have questions along the way, please let me know.