I have a 99 Windstar with rear heat unit. My problem is that I get no heat from unit, only cold air. A/C works fine, Front heat works fine. Lines going into rear heater core both feel hot. Is there a blend door on rear unit or may the control valve be bad? I also now have the lean banks indicator codes (171/174) but that is an issue for another time. Any help with my heat problems would be greatly appreciated.

You do have two doors in your rear unit. One is a blend door similar to the front. One is "mode" ...up/dwn. The actuators are the same.

If you find the blend door actuator bad... you can "steal" the other one. You won't miss the "mode" function.

Welcome fellow 99' er. I assume a 3.8L.

I know you mentioned that the 171/174 was for another time but I thought I would add in that there has been a lot of very recent threads on this topic so search away. We also have several backyard mechanics who have performed this repair themselves and the general consensus seems to be that if you are a wrench turner than it is a relatively easy repair to do provided you have about 3 or 4 hours.

Highlifesipper wrote:

I too ass-ume the 3.8L. What's up, DWR100? Thought I would see a reply from you here since Engine5LT mentioned the 171/174. Check it out, Engine5LT. As soon as you start having driveability problems or even before you should start reading all threads conserning 171/174/isolator bolts/valve cover/TSB03-16-1. Click on my name and send me an e-mail with a fax number. I will go out of my way to fax you the Technical Service Bullentin TSB that concerns this problem. There's also some posts here that have the TSB, but a hard copy in your hot little hands is alot better. I'm serious. I will help. Anyone else who needs the TSB, send me an e-mail. Hope you get your heat fixed, E5LT.