Jump to content

HVAC Actuators not working

E P

By E P
in Troubleshooting & Recalls

 Share

Recommended Posts

E P Enthusiast

E P

Posted
Posted

Hey everyone,

 

Parked my 2015, left for work for 6 weeks, came home and found some sort of rodent made a nest in the cabin filter. 

 

All was well, but my HVAC Actuators aren't working. I tore most of the dash apart, removed the filter, blower motor, etc to access the mess they made behind the dash and got that all cleaned up. 

 

I ordered some new actuators, plugged a new one in and the actuator itself won't work. I can move the cam with my hands and everything works and is free. 

 

All I can think of is somewhere down the circuit, the wires may have gotten chewed. But what's strange is that none of the actuators themselves seem to be working. I believe there's 3. Driver blend, passenger blend and the mode actuator located to the left behind the glove box. None will work. I've attempted to locate a fuse, changed all the ones I could find related to AC/HVAC. 

 

Anyone have any ideas where to start? I've got 60% of the dash apart, but before I commit to a full teardown I figured I'd post here and get some advice. Even a wiring diagram for the blend doors would go a long way. 

 

Thanks! 

E P Enthusiast

E P

Posted
  • Author
Posted

I couldn't find an RPO for C67 or C42. I have C49 listed in my glovebox. 

 

Tried yanking fuse 26 on the driver side interior fuse box to perform an HVAC reset, still nothing. Seems like I'm not getting any power to the actuators. 

tbarn Senior Enthusiast

tbarn

Posted
Posted

C49 is rear defrost. How about CJ2? Or better yet a VIN.

E P Enthusiast

E P

Posted
  • Author
Posted (edited)

I've found a wiring diagram, and haven't been able to find any faulty wiring. This has me scratching my head. I have power going to the HVAC control module, but the actuators aren't working. 

 

Just trying to save myself from taking off the steering column to get the dash off but I might have no choice. 

 

According to my diagram, all the actuators are tied in through the black/yellow wire and grey/red. 

 

 

Edited by E P
tbarn Senior Enthusiast

tbarn

Posted
Posted

CJ2 it is. Check for 5v, 12v and grounds per diagrams. otherwise you will probably need a scan tool and diagnostic chart.

Screenshot (28).jpg

Screenshot (29).jpg

E P Enthusiast

E P

Posted
  • Author
Posted

I ended up finding the issue after getting the dash off and tracing wires. Something chewed the wiring up right up behind the mode actuator, near the firewall. 

 

I'll probably have to yank the HVAC case to access the other end to splice it. What a nightmare. 

  • Like 1
E P Enthusiast

E P

Posted
  • Author
Posted

 3 identical black and yellow wires. I've spliced all the others, can't get the actuator behind the glovebox working.

IMG_20250305_135516115.jpg

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.

  • Forum Statistics

    250.4k
    Total Topics
    2.7m
    Total Posts

  • Member Statistics

    342,760
    Total Members
    8,960
    Most Online
    MASONV88888888
    Newest Member
    MASONV88888888
    Joined

  • Who's Online   2 Members, 0 Anonymous, 1,475 Guests (See full list)

  • Latest Articles

  • Posts

    • MASONV88888888
      Another 6.2L engine failure!

      By MASONV88888888 · Posted

      My 2025 Silverado 1500 had to receive a brand-new engine (long block) under warranty last month at only around 16,500 miles. Before the replacement, the truck repeatedly displayed "Engine Oil Level Low" warnings, even though the Oil Life Monitor still showed around 50% remaining after about 6,000 miles since my last oil change. After seeing the warning several times, I checked the dipstick with the engine cold, and the oil level was completely normal. The next day, the message escalated to "Add Engine Oil." At first, I assumed it was just a faulty oil level sensor, so I brought the truck to the dealership. After inspecting the engine, they found internal cylinder wall scoring and ultimately replaced the entire long block under warranty. Before this happened, I was planning to install a 4-inch lift and suspension upgrade on my truck. After needing a new engine at just 16,500 miles, I honestly don't see the point anymore. I also contacted GM to ask whether my vehicle qualified for a buyback, but I was informed that it does not at this time. Anyway, this experience has left me with serious concerns about the long-term reliability of this engine. I sincerely hope NHTSA expands the current investigation or recall to include 2025 model and performs a thorough inspection of affected vehicles. My biggest concern is that these engines may fail shortly after the powertrain warranty expires. If GM truly stands behind this engine, then at the very least, please consider extending the powertrain warranty to 10 years for affected owners. That would go a long way toward restoring customer confidence.
    • Grumpy Bear
      OCI, not when but why?

      By Grumpy Bear · Posted

      Without exception but then I'm the odd duck, right? I know what goes into that test, how it is calculated and thus how to beat it. But EPA values are often not beaten by the general public and the government has in past years adjusted the means and methods to come to those values to more closely approximate "Joe Average".    The only real trick to beating that EPA average is don't drive like "Joe Average".    It's the same method you used to profit from "Economic Migration" and in doing so beat the 'stats'. But you, like me, are not "Joe Average".     The thing you don't seem to grasp is this "Purchasing Power Index" isn't forward looking. It doesn't predict what it going to be but looks backward and states what it was. They are not telling us what the THINK, they are telling us what they MEASURED. Example:    Wife says "I'm going to lose 40 pounds by Christmas". May she does, maybe she doesn't but the doctors office who weighed her when she made that statement and again at Christmas only REPORTS what the RESULT was. You and I can banter about what was possible and what aunt Tilly did till the cows come home but the result is the result. Arguing otherwise is.....irrational. That's all I'm saying. This isn't about:      What you are calling a 'Statistic' is a RESULT not a CALCUATION and as a result the RULE. Like gravity as a rule, it can not be broken. 
    • MASONV88888888
      Rattle in the rear!

      By MASONV88888888 · Posted

      Just wanted to say thank you for posting this. Years later, your thread is still helping Silverado owners.   I bought my 2025 Silverado 1500 in January 2025, and I've had what feels like the exact same rattle since day one. After reading your findings, I believe my truck has the same issue with the cable carrier contacting the rear sliding window. To be honest, I had pretty much given up on pursuing the issue. It wasn't until I recently drove another brand's pickup that I realized just how quiet their cabin was—and how noisy mine has been all along. On my truck, the rattle happens on almost any paved road, gets even worse on rougher pavement, and I can even hear it during braking and acceleration.   I actually referenced your thread when submitting my case to GM, hoping they'll recognize this as a recurring issue instead of treating it as an isolated incident. The reason I reached out to GM first is because my dealership told me they would need to keep the truck for at least two days just to diagnose the problem. I was concerned that even after two days, they still might not be able to identify the source of the rattle before giving the truck back to me. I had also asked a few dealerships about this issue during previous service visits, but none of them seemed to know what was causing it or had a solution. That's why I decided to contact GM directly first, hoping they might already have an official repair procedure or guidance for this issue.   I also hope GM eventually comes up with an official fix for this problem. I have a feeling there are many Silverado owners experiencing the same rattle, but most either choose to live with it or simply don't know what the cause is.   Really appreciate you taking the time to document your diagnosis. Your post is still making a difference years later.
    • Buckwild27
      Gas Prices

      By Buckwild27 · Posted

      I have 2 choices. 
    • Grumpy Bear
      Gas Prices

      By Grumpy Bear · Posted

      Do you have access to BP fuels? Some stations have Silver 91 E-0 priced the same as their 93 E-10.  There is a local Marathon with 90 alky free for $6 a gallon but I go down the road to BP for $5-ish. They also have a 100 E-0 but that stuff is $10 a pop. 

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...