Lincoln/Mercury Repair: 98 Taurus no heat, ground cable, degree air

Question
Hi Dinger, would like to get your expertise if I can.  I was looking at a friend’s 98 Taurus today that has no heat.  The car gets plenty warm, but just blows out cold air.  When I turn the knob from cold to hot, it gets about 50 degrees.  When I turn it back to cold, it’s about 35 degrees.  I located the hoses going to the heater core under the hood.  The top one was not hot – at best lukewarm.  The bottom one was extremely hot to the touch.  I noticed that those heater core hoses can bypass the heater core.  I tried clamping off the bypass, which made the heater blow out about 80 degree air, but still not hot.  What would you suggest?

Answer
Hi Greg,

There is a blend door under the dash, passenger side. It's electronic, so check it for operation. I see that it calls for Just .7 of an hour to replace. There is a TSB out on this issue.

REMOVAL

1. Disconnect battery ground cable.


2  Disengage console panel from instrument panel reinforcement and remove from instrument panel.

  

3. Disengage console panel from RH side of center console finish panel if equipped. 4.   Working from under the passenger side of the instrument panel, remove A/C electronic blend door actuator electrical connector from A/C electronic blend door actuator.

  

5. Remove four screws retaining A/C electronic blend door actuator to the A/C evaporator housing and remove A/C electronic blend door actuator from A/C air temperature control door.

INSTALLATION

1. Insert actuator shaft into A/C air temperature control door and secure A/C electronic blend door actuator to A/C evaporator housing with four retaining screws.

2. Install electrical connector to bracket on A/C electronic blend door actuator.

3. Install instrument panel insulator and console panel if equipped.

4. Connect battery ground cable.

If you saw, under the hood, a vacuum operated diaphragm that possibly controls the flow of hot water to the heater core, I would start there first. This would be an older type of system though and I couldn't find anything on it. All I could find was on this blend door. I think maybe they did away with the vacuum style diaphragm and went to this electronic doohicky. It's located behind the glove box. I wish I could send you a pic, but they don't let me in this medium.

Ok, my fingers are tired! LOL Good luck with this and let me know how it turned out.