No Heat on floor

[mrkistle]

I just purchased the truck...1996 Ranger, standard cab, 3.0, auto , ac, ps.

I noticed over the weekend that I have no heat. I switched from the floor to the dash vents, and there is heat, but there is cold air still blowing on my feet. I've researched but couldn't find the same issue, and the only thing I can thing is a vacuum leak or vacuum heater actuated valve. Anyone have this problem before???

 

[Earl43P]

Have you read this one?
A lot of good valve location/operation info there.

http://www.therangerstation.com/Magazine/Summer2009/blend-door.htm

 

[mrkistle]

I read that, but if it was the blend door, I wouldn't have heat at all.

Also, just went out to lunch, and the heat worked at low speed...so, I'm still researching.

 

[Earl43P]

If you mean that you have "some heat" with the blower on low speed, that does NOT mean that the blend door is operating properly. Low fan speed allows better heat transfer than high speed.

If you mean that you have "some heat" when you are driving slowly down the road, then I would want to know what the coolant temp gage is doing. I would immediately suspect the fan clutch is stuck engaged, but you should hear that roaring when you drive.

It is really easy to observe the blend door actuator. Fully open the glovebox, squeezing the sides, so that its entire contents dump onto the floor. After shutting OFF the engine, operate the temp knob 3:00 to 9:00 and LISTEN for the actuation of the damper/door WHILE you watch the actuator/spline. I makes audible thumps.

There should be plenty of vacuum stored in the sphere reservoir after shutting off the engine to do this test in the quiet, plus let you change the vent/floor/defrost position and listen for those doors too. If there's not, THAT's a problem too.

 

[mrkistle]

Should have noted this in the first post. The temp gauge is right in the middle.

I have heat on the floor when I'm driving slow. When I'm on the expressway, I get heat from the dash vents, and cold on floor at the same time. When I put the heat on the floor, it is just cold. I have heat through the dash vents at all driving speeds. I assumed that since I get heat from the vents it wouldn't be the blend door or the core...then again, I'm new to tracking down these gremilins.

I'll check the blend door tonight
Thanks for the quick responses...

 

[mrkistle]

So the heat is now working...Could this be the actuator motor?
I checked the blender door and it made the thumps and the arm moved, so I assume it is working.

any ideas???

 

[mrkistle]

Update:
What I found is the heat works, but outside cold air would blow in from outside from the passengers side of the dash, but not from the floor vents. The floor vents would blow heat. I decided to replace the blend door, and found that a prior owner had replaced the blend door, and the blend door worked fine. They just forgot to tape up the hole that they cut. I'm going to assume this is the problem I was having with the heat. It is just too hot to test it. Hopefully, it will get colder in the mornings over the next few days.