oklumberman

This sight has been great tool in diagnosing and fixing my truck, however I need some expert advice as I haven't been able to find exactly what I need via searching / creeping the forums

I have 2 problems:

Truck 2010-F150 Lariat 4x4 - Flow through console heated / cooled seats / dual climate etc

1: No heat - Started out just affecting the passenger side only, no doesn't work at all. in the forums I have found it could be the control unit in the dash, one of the (two?) blend doors, or a vacuum problem? Any suggestions on how to narrow it down? Lines going into the heater core are hot and flowing. (addendum) My heater / ac fan will not change speeds (stuck on high speed - though this might be a completely separate issue? Resistor?

2: 4x4 problems - so far I have had the vacuum lines that disengage the hubs repaired twice because (once on driver side, once on passenger) line broke, 4x4 was half engaged and hubs would grind when making a turn.

Since then everything has seemed fine, however, when it's really cold outside the driver side hub seems to not fully disengage and will grind just driving straight, when the truck warms up, or in warmer weather problem goes away.

Are these two problems related?

Any help in narrowing down the climate control issue would be much appreciated, and some insight on the root cause of my 4x4 problem also.

THanks in advance