Friday, July 17, 2015

Shade-tree Saturn Ion Mechanic Tips #2: HVAC Control Panel

OK. Here we go on another guided repair of the beloved 2003 Saturn Ion 3.

This time we are working on the HVAC control system.


Over the past 1-2 years I noticed that the blower fan speed seemed to be getting “weaker”.

I eventually couldn’t tell any blower fan output difference between the speed 1 & 2 positions. The 3 position seemed OK and the 4 position seemed a bit faster.  Changing out the cabin air filter is a easy place to start (and needs to be done regularly) but that didn’t help.

Since it is hot on the Texas Gulf coast, being set on 3 or 4 didn’t seem to matter.

Then about two months ago, Lavie and I were riding around town, she got too cool, and she turned the selector down to 2. The fan cut off.  I moved it back to 3 and it was OK. However moving the switch position to 4 or to 2 or 1 caused the fan to cut off entirely. Hmmm.

So I lived with that for a few weeks, but then even 3 stopped working.  No more fan meant no more AC meant Claus was a very warm boy.


  • Checked the HVAC breaker, it was fine.
  • HVAC Dash Control Unit - well the rear-window defroster button worked. The in-cabin air recirculation button seemed to work. The ventilation selector knob turned normally and the temperature selector turned. Not helpful information but OK.
  • The blower motor seemed to be running normally right up to the failure event. only problem was I (gradually) couldn’t select the speed.

To the Forums:

Based on a read of these posts, I was pretty confident that blower control switch in the control panel had failed. It seemed like a fairly easy self-repair if I could just find the part and the time.

This video by richpin06a on YouTube sealed the deal. Note the demo car is a salvage so all the extra disassembly you see isn’t related to the specific task at hand.

To find the Parts:

First step was to call the dealership.  Estimated cost for OEM part via the dealer was in the $275 range. Ouch.

So I started looking around for an OEM part.

Vehicle: 2003 - SATURN ION - L4-134ci 2.2L

    • Group: Heating/AC
    • Subgroup: AC Relays and Switches
      • Heating and Air Conditioning Control Panel with Rear Window Defogger Switch
        Part Number:  10388471
        Product Notes:
      • HVAC Control Panel
        AC Man Cont(C60) ; 1 Per Veh
      • Per Vehicle: 1; Years: 2003-2005

Putting in the part # I then found that Amazon is an authorized ACDelco part supplier (who knew!) and so I ordered it from them.  Current price at time of posting is just $121.41

Thanks to Amazon Prime it arrived two days later and was in pristine condition as a new part should be.

dgoebs4r.bpp  yy0e4kah.0mz

The Swap:

Again, brother and I had watched richpin06a’s how-to video until we had it burned in our skulls so we were set with the process. We set aside an hour to perform the task (underachievers that we both are).

I had a full mechanic’s toolkit at the ready but brother had also brought a 7mm flex shaft spanner and a hand-held pry tool. We ended up just using those. Here are some samples in case you are interested:

First begin by removing the negative terminal from the battery post. It’s located in the trunk under the floor cover.  Note the photos below show the clock still on. These are retaken this morning as we didn’t capture pictures during the actual swap as planned. Please remove the power from the battery to be safe! I didn’t do the battery disconnect as I was only removing pieces but not fully disconnecting them.

The dash:


In the end rather than using a pry tool, I just reached into each vent and firmly tugged and pulled forward until I was able to release the metal clips from their slots. Doing so ensured I didn’t damage the plastic trim. The metal clips are strong, but once started, I was able to work by way around and get it released.

Here is a view after it is fully removed so you can see the metal clips and where they are located for reference.


Once the top is pulled open, gently unclip the hazard light harness connector from its button.


Then you can fully remove the trim cover insert. you can see the corresponding clip insert slots as well below. They are molded in the plastic so don’t go crazy pulling on the clips but it held up fine for me. I highlighted the only bolts  you will be working with.


Remove the car radio next (I noted down all my radio pre-sets first before disconnecting the battery to make resetting them fast).

Unscrew the two upper bolts along side the radio unit.  The bolts are long. You can back them off almost even to the outer trim. Be careful to get a good hold on them when you extract them or you might drop them inside the center console which can be a headache to re-find depending on how they bounce!

The radio is connected by three points, a clip-on ground wire (pull off), an antenna wire (pull out), and a harness connector (unclip).  Just handle the connections carefully and you will be OK. Note the view below shows the radio unit rotated 180 degrees (upside down). That make access to the cables for removal a bit easier that “right-way up”.


With the radio removed you will have better access to the next stage of service. Note that the OEM GM radio does have some anti-theft technology that will disable the radio in certain conditions. Some people were worried about that and didn’t want to pull it out. I didn’t have any issues with fully removing/reconnecting it and it works just fine with no security reset required.

Don’t try to unscrew/remove the HVAC control unit head module yet. Trust me. There is no slack on the mechanical control cables so you will have to disconnect them while the unit is mounted.


The video makes removing the cable connectors seem pretty easy. It took me a bit of work and knuckle banging to get them released. I was about to use the pry tool but as my brother was handing it to me, I finally was able to get each of them unclipped and unhooked. If you look at them (or your replacement part) carefully, you will see it is more of a “spread-apart and pull cable straight up” motion.

Left side cable connection


Right side cable connection


Then unclip the two wiring harness connectors.

Now that all the connectors are free, unscrew the two bolts to each side of this HVAC control head module and lift it up a bit, then pull it forward and free.

All the hard work is now down.

Reverse the steps for the reinstallation.  The control cables go back on much easier.

Once we had everything put back in place and done, battery connected, we turned the car over and tested the AC and the controls.  Hazards worked, radio worked, defroster button lit, vent selector knob turned free with no binding, same for the temperature knob. The fan speed selector worked and a different blower speed was felt for each of the four positions (yea!) and the A/C and recirculation buttons worked fine and lit up as well.  It took a while for the cabin to cool down but the A/C worked great.

Total repair time for the two knuckleheads (IT sysadmin & process safety engineer): 15 minutes tops from battery disconnect to full reassembly and testing.

Problem solved!

Part Comparison:

You can see in this picture that the blower switch selector appears to have burned out for some reason as there is clear melting of the housing compared to the new part.

Failed part with plastic melting - click to see fuller size.


Good part - click to see fuller size.


I suppose I might have been able to find just the switch part itself and swap that out, but for only $121 for the entire assembly it wasn’t a big deal to me and I was sure I was getting all new parts/electronic board/switch parts/etc.

Here are some photos of the breakers as well for the curious;

Breaker panel in the driver side foot-well. Turn the little upper-left screw with a nickel to open.


Guide label on reverse:


HVAC breaker itself in position and noted.


Saturn Parts Supply Part 2:

I had great luck finding this OEM part on Amazon but here are some other Saturn Ion part resources/vendors you might be interested in checking out for comparisons or other parts needed:

What was particularly invaluable for me was finding the part schematics that many vendors (such as GMPartsCenter) have online. This not only lets you verify the exact part/# you are looking for, but you can also do some detective work to figure out how the parts and assembly fit together so you can work out the service steps if there are no guides.


Claus Valca

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