Heater blend door problem

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Nov 11, 2008 | 05:38 PM

nickmobile67

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From: East Coast

Heater blend door problem

My 86 F150 with air, the switch between floor and dash vents stopped working. I took the face off of the heater core and I can see the door get stuck half way before it moves all the way over to floor vent position. Is this a common part to break? What do I have to do to fix it?

Nov 11, 2008 | 05:48 PM

Holmesuser01

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From: Asheville, NC

My 83 is doing the exact same thing. This will be interesting.

Last edited by Holmesuser01; Nov 11, 2008 at 06:09 PM. Reason: Wrong reply.

Nov 11, 2008 | 05:50 PM

Blindbatts

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From: SoCal...Camarillo, CA

are you sure you don't just have a vacuum leak going to the switch?

Nov 11, 2008 | 07:11 PM

nickmobile67

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no there's not a vacuum leak, the motor is working fine but the door is physically binding up when it gets about half way to the floor/defroster mode. I really don't want to take the whole box out of the truck. I put some duct tape on the hing side of the blend door to keep it from coming loose and binding but it only worked for about a week.

Nov 11, 2008 | 07:24 PM

86Stepside

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From: Minneapolis, MN

I just fixed the same thing on my truck a few weeks ago. If you take the top dash pad off, you'll get a better view of the ductwork, when you do that you'll see that the ductwork for the passenger side vents need to come out to access the "door". Since the door is broken you can probably see the hinge on the back to pull the pin out. Putting the new door in will be a little harder, especially if you have big hands, because you need to go through the hole next to the door to put the pin in the hinge. It took my a weekend to do it, including a trip to the junkyard for a replacement.

Nov 12, 2008 | 09:02 PM

Chevy_Eater

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I just went through this myself. It's kind of tight, but you can do it without pulling the box. Like 86 said, pull the dash pad, then the braces and ductwork. Basically gut the top half of the heater to get to it. I couldn't find a new replacement and all the ones at the junkyard were either already broken or so weak and brittle they broke as I was removing them. What I ended up doing was cutting a couple of strips of inner tube, drilled some holes in both pieces of the door and used pop rivets to secure the tube pieces. Basically rebuilding the hinge with rubber. Works good so far.

Nov 13, 2008 | 04:55 PM

Holmesuser01

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From: Asheville, NC

This is so ironic.

Last weekend, I replaced the heater core in a 1985 Oldsmobile Toronado. From start to finish, it took 9 hours. I had to pull the whole dashboard and instrument cluster, etc, just to get to the heater box. After I got the bad boy off of the firewall, it took about 5 minutes to actually replace the heater core. Its all plastic.

Now, it looks like I get to do a portion of this job again THIS weekend on a truck that has seen 4 owners before me, and the last 2 were heavy smokers. If for no other reason, I'll go ahead and pull the box from the firewall and clean it all up before I put it all back together. I was lulled into a false sense of security when I replaced the Ford core in less than 1 1/2 hours.

I'll let you know how mine goes.

As for the homemade parts, it will probably last forever in there.