No heat in cabin

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
6,448
Likes
80
Points
48
#1
Make
Ford
Model
F-150 2WD
Year
1999
Miles
unk
Engine
4.2 L V-6
I'm just getting into this. As it warms up both heater hoses are heating, before the top rad hose is flowing; so I'm kind of assuming there is flow through the heater core. I need diagrams showing how I can reach in and make sure the core is getting hot, and how to check the blend door. I'm expecting it is something to do with the blend door.
 

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
6,448
Likes
80
Points
48
#3
Thanks. The video was kind of jerky and blurry, but shows what I need to know. I don't have the '99 here right now, but it is similar if I'm remembering correctly.
 

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
6,448
Likes
80
Points
48
#5
Thanks, that also helps; same story, but told better. This video pointed out the T&G on the box that needs to be cut and, more important, where the A/C evaporator is that you want to avoid cutting into! Unfortunately, neither video shows the actual cutting process. That's not important to me, I am an accomplished "artist" with a die-grinder and such, but actually showing ways that can be done would be helpful to a newbie. Too bad only the grinder was shown, not also the type cutter to use in it...
 
Joined
Mar 1, 2002
Messages
3,574
Likes
59
Points
48
Location
Kentucky
#6
When I cut into a hvac box, I usually use a thin blunt knife blade that I heat with a torch. I bend the blade to get into awkward areas. Get it red hot so that I can cut with delicate pressure, reheating often. Plastic melts, a metal core won't. If I am going in blind, I will make a small hole first, then look or feel inside to see what the situation is. Small holes are so easy to patch with the "shiny metal tape" that I will always make several small holes rather than a big one.
 

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
6,448
Likes
80
Points
48
#7
"Plastic melts, a metal core won't."

Ah, a common-sense tip that is priceless! I won't have any trouble, but your's is certainly the method that should have been mentioned in both those videos.
 

grcauto

Hero Member
Joined
May 29, 2014
Messages
565
Likes
33
Points
28
#8
"Plastic melts, a metal core won't."

Ah, a common-sense tip that is priceless! I won't have any trouble, but your's is certainly the method that should have been mentioned in both those videos.
Vacuum lines and wire insulation is another story. Regardless how you do it just be careful and you'll be OK.
 

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
6,448
Likes
80
Points
48
#9
I think of wires insulation as being the same story. Sure, you could nick the insulation with thermal, but the wire will still be intact. It is a lot easier to tape over a bare spot in the insulation than splice the whole wire.
 

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
6,448
Likes
80
Points
48
#11
I am "bumping" this back to life only to have it handy when I want the videos. We are now finally working on it.
 

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
6,448
Likes
80
Points
48
#12
Well, crap! We went at it from the wrong end. The door is fine, but the actuator isn't working right. It doesn't sweep full range but kind of dithers in just one position. Yes, this is with it away from the door, nothing binding. Opened up (and it does open very easily) there is nothing obviously wrong, like a stripped gear, and if the feed-back pot in there is disabled the motor runs fine continuously.

So, I need whatever info I can get about that actuator circuit. It is a 4-wire connector, that is all I know right now. I would like to do some testing to determine if the problem is in the actuator or dash control (a pot?) that sets it, or the wiring. I can probably figure out which wires are power and ground, although they seem to be OK, but the other two wires not-so-much.
 

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
6,448
Likes
80
Points
48
#15
Thanks Dan. I haven't looked at the above yet, but it is a 5-wire cable on an 8-pin connector. I didn't look at it closely enough last night...

Yeah, that schematic is what I'm looking for.