Hvac help

[tRidiot]

I don't remember what it was doing exactly - either hot or cold, it was 8+ years ago. I took it all apart, found the blend door and noted by the markings on the outside it looked like the blend door had traveled outside the track, beyond the 'stops'. I opened it up and verified it could not travel because it had overtraveled the stops. I then reset it manually, taking the gears out and putting back within the stop margins - but every time I tried reinstalling and resetting it via the reset/relearn procedure, it kept doing the same thing - overtraveling. Replaced the blend door with one off Amazon (probably Dorman, didn't know any better years ago). Same issue. Also looks like I replaced the sending unit upstream, again I don't remember, but Amazon tells me I bought that part.

So my fix was to take apart the blend door actuator, manually set the gear where I wanted it, in the hot or cold position, then mount it back to the blend door, rotating the blend door to fit into the hole in the actuator and it would hold the blend door in the hot or cold position when I screwed it down. Then I just didn't hook up the plug to the blend door actuator so it didn't receive any signal from the sending unit, because I knew it would cause it to overtravel and jump the stops again.

I repeated this process a couple times a year to switch between hot and cold.

I'd like to be able to solve the problem. I have a brand new AC Delco blend door actuator, but when I tried it and the 'reset' procedure, it didn't move, so I removed it and reinstalled the old one, as I didn't want the AC Delco one to get destroyed. Now that I have my Tech 2 clone, hopefully someday I'll be able to figure out if parts are actually communicating properly and can be manually controlled, etc.

Hope that makes it all more clear.

I might be able to tear it apart and take some pics this weekend or something.

 

[roadrash187]

I don't remember what it was doing exactly - either hot or cold, it was 8+ years ago. I took it all apart, found the blend door and noted by the markings on the outside it looked like the blend door had traveled outside the track, beyond the 'stops'. I opened it up and verified it could not travel because it had overtraveled the stops. I then reset it manually, taking the gears out and putting back within the stop margins - but every time I tried reinstalling and resetting it via the reset/relearn procedure, it kept doing the same thing - overtraveling. Replaced the blend door with one off Amazon (probably Dorman, didn't know any better years ago). Same issue. Also looks like I replaced the sending unit upstream, again I don't remember, but Amazon tells me I bought that part.

So my fix was to take apart the blend door actuator, manually set the gear where I wanted it, in the hot or cold position, then mount it back to the blend door, rotating the blend door to fit into the hole in the actuator and it would hold the blend door in the hot or cold position when I screwed it down. Then I just didn't hook up the plug to the blend door actuator so it didn't receive any signal from the sending unit, because I knew it would cause it to overtravel and jump the stops again.

I repeated this process a couple times a year to switch between hot and cold.

I'd like to be able to solve the problem. I have a brand new AC Delco blend door actuator, but when I tried it and the 'reset' procedure, it didn't move, so I removed it and reinstalled the old one, as I didn't want the AC Delco one to get destroyed. Now that I have my Tech 2 clone, hopefully someday I'll be able to figure out if parts are actually communicating properly and can be manually controlled, etc.

Hope that makes it all more clear.

I might be able to tear it apart and take some pics this weekend or something.

I had the same issue on my rear. Except it snapped the nipple on the blend door itself instead of the stops.

Ill try and find the video I used. I know on my actuator it was past the markings so it wouldnt move. Had to use a 9 volt battery to bring it back into spec. Been workin like a charm since.

 

[roadrash187]

 

[tRidiot]

So the problem is in the actuator itself, not being 'overdriven' by the controller?
That's interesting, I'll have to watch that video later and see if there's something I can do to fix things.

 

[roadrash187]

So the problem is in the actuator itself, not being 'overdriven' by the controller?
That's interesting, I'll have to watch that video later and see if there's something I can do to fix things.

Let me know how it works out for ya. I ordered new air duct sensors, sunlight sensor, and the one above my head. Hoping I have a bad sensor in the roof or the dash. Before I take apart the dash and start inspecting the wiring harness and replacing the duct sensors on the front blower box. If I find a solution Ill post the update.

 

[tRidiot]

Oh my God, I started off looking for a 9V battery adapter with those open-pin terminated ends - now I've been down a rabbit hole looking at wire termination tools for quite literally 3 hours, ending up reading about Dupont connectors and the variable quality of the crimps offered by tools going back to the 50's.

<sigh>

If anyone wants to read up... here ya go. http://www.mattmillman.com/info/crimpconnectors/