Hvac help

[roadrash187]

Need help with my system. Installed both a new blower motor, resistor, and control panel. Spliced in the harness that came with the new resistor. It will still cut in and out. Im at a loss and dont know what else it could be. Could it possibly be one of the temperature sensors even though its not set on auto?

 

[OR VietVet]

Are you still having the same initial problem or is the current problem different? Product component manufacturer? Please do not say Dorman.

 

[tRidiot]

Unfortunately for some things, Dorman is all you can get. I know my rear AC is borked and while I replaced the blend door, the control unit is discontinued and no longer available anywhere. So I'm just screwed forevermore, I guess.

 

[Doubeleive]

If you have the manual control hvac what happens with those usually is the metal contacts inside get funky and don't make good contact anymore you can take them apart and clean the contacts and put them back together and usually it will work fine again

 

[roadrash187]

Are you still having the same initial problem or is the current problem different? Product component manufacturer? Please do not say Dorman.

I forgot to add its for my Denali. So it has digital controls.

The controller is from Dorman. The resistor and blower motor are “AC Delco” from Rockauto.

I replaced the blower motor and resistor back in Aug. with some brand off of Amazon. So I figured it was cuz of some no name brand. But Im thinkin of trying to find an OEM controller off of ebay and hope for the best.

 

[OR VietVet]

ebay is a source for the controllers.

 

[tRidiot]

If you have the manual control hvac what happens with those usually is the metal contacts inside get funky and don't make good contact anymore you can take them apart and clean the contacts and put them back together and usually it will work fine again

I'm sure mine is the controller or something. I buy a new blend door, go through the relearn/reprogram procedure and it overdrove the door and it jumped track. That was years ago, I've been manually changing it twice a year for 8 or more years now. So I bought a new AC Delco door and it wouldn't change at all. I deinstalled that to protect it, and looked at the part upstream - the controller. When I plugged that number in at Amazon, it told me I'd bought that same part back in 2014 or something. <facepalm> A Dorman, of course, but you can't get the AC Delco.

So I dunno what else to do. I bought a Tech2 clone so I could try to manually operate things and see what is going on - I just don't know how to use it. And haven't had the time to learn.

 

[Fless]

Sometimes there are updated calibrations for the controllers, available standalone in TIS2000 with an XP computer, or through the GM online programming system. I believe you'd need to know the part number of the controller you want to update, since there seem to be several different calibrations, each unique to the module.

Out of curiosity, if you post up the GM part number of your module, I could try to see if an updated calibration is available. But you'd also need to use your Tech 2 to see what the current calibration is on it.

 

[tRidiot]

Man it would be awesome to be able to get my rear AC working properly again. I am just going to have to watch some videos and learn how to use this tool.

 

[roadrash187]

Is yours just blowing out cold air on the rear no matter the temp setting?

 

[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/