Rear blower inop
 

I have a 2004 Suburban with automatic a/c controls. The rear blower is not working. I checked for power and ground at the blower, and had neither. I replaced the blower motor control module with the new updated model. It is still inop, so I checked the wires at the module and realized I had power ground, but no reference voltage on the purple wire. I borrowed a Modus scan tool from the Snap On dealer and and was able to read inputs for the the blower control from both the overhead controls and aux controls, so that pointed to a bad HVAC control module-auxillary. I changed out the module and still have no reference voltage coming to the blower control module to turn it on! I Ohmed out the purple (ref voltage) wire from the blower control module to the HVAC control module and it is good! I have supplied power and ground directly to the rear blower, and it works. I'm starting to feel lost and am not sure what the check next.

My 2004 surburban does the EXACT same thing! All my checks are EXACTLY the same!! What did you do to fix it??!!??

I found out that using a multi-meter to check for power at the blower control module was giving me a false voltage.....it showed 12+ volts, but when I put my test light on it, it would not light up. So make sure you really have enought juice on the main power wire to the blower control module to light your test light. If not, you should find a burnt wire at the connector behind the kick panel at the parking brake. I just cut the wire at both sides of the connector, and spliced them back together.

Is this old or did you fix your problem

Not sure if this are old post or current issues but I just fixed mine and if you need info let me know. Maybe I can help.

Mine works sometimes and sometimes it doesn't. What did you do to fix it Helpu?

Looks like u are on the right track. Was it the FSR module for the Rear AC blower you replaced or was it the Rear AC overhead Control Module above the front seats you replaced?
I am assuming that your rear AC blower runs normal if you jumpered the power(12vdc) wires at the FSR, correct?

Do not waste your money on the Online mechanic as I did. They did not seem to understand the troubleshooting I did just like u and I ended up being very frustrated and pieced together info from other posts to fix mine. Here's my email in case we get lost: filsua@yahoo.com

Take a pic of your FSR and indicate input power wire color(from the battery or fuse) and the output(to the blower) wire color as the non EOM FSR have different color wires---it was on my 2000 Sub. Also indicate the GND wire color and the sensor wire. A pic of the wires connected to unit(normal) is better

Hello rtkachuk. Not sure if I replied to your question already. Tell me what you have done/troubleshoot so far and your mech/auto elect savviness

If I tap the passenger rear cargo area plastic shroud the blower kicks on. Could this be the motor? If so, do you have a part number?

Sounds like you might be in luck and something minor. Could be a loose wire/connection. Take off the 1/4 panel and check the connections on the blower FSR unit. Check your ground wire while you're at it make sure it's not loose make sure the nut is on tight. Check the blower make sure there is nothing jammed in there causing it to be intermittent. Motors either good or no good, there is no in-between. Also check the thin wire(sensing wire---purple) for good connection. I did not need to replace my blower motor( so I would not have a part # but that's an extreme case and I tend to think your problem is not the motor.

Sounds like you might be in luck and something minor. Could be a loose wire/connection. Take off the 1/4 panel and check the connections on the blower FSR unit. Check your ground wire while you're at it make sure it's not loose make sure the nut is on tight. Check the blower make sure there is nothing jammed in there causing it to be intermittent. Motors either good or no good, there is no in-between. Also check the thin wire(sensing wire---purple) for good connection. I did not need to replace my blower motor( so I would not have a part # but that's an extreme case and I tend to think your problem is not the motor.

No power to rear AC 2005 Chevy Tahoe
 

I was wondering if anyone could give me some intel on my rear AC problem. I am not getting any kind of air from the rear ac. I use the front and rear controls and no luck. I have not done anything to it at all because I wouldn't know where to start . Can someone please help . Thank you

Hello
Still having AC issues? Give full details of the issues you are having and what you have done so far. Reply to this email as I am not good with navigating the forums. I had an initial AC issue last year I fixed myself for $30 instead of $1200 at dealer, troubleshooting then replacing the Aux. rear AC control module but then a month ago I ran into another issue which I fixed myself for $60 instead of $500 at the delaer. Every little detail is very important for good diagnosis and hopeful I can help resolve your AC issues.
Thx
Filipo

1. Is the front AC and Heater running normally
2. From what you said, the rear Blower does not come on at all when the controls(rear) are in right settings correct?
3. Does your car have both a front and rear overhead console controls for the rear AC? and you have set these controls in the correct positions but still no rear air, correct?

You can reply here. I can get ur message

U can reply here. I can get ur message now

ok so my rear ac is not working at all it does not turn on! I will turn on the front one and use the AUX in the back and the front and nothing . I haven't tried anything at all to repair it .

Can't help if you do not give good information.
What is your level of mechanical or electrical know how?
Answer the three(3)questions I posted directly and individually.. Do not bundle the answers together as it gets confusing

1.yes they are running normal
2.that is correct no air comes out of the rear vents so I assume the blower is not coming on
3.yes it has a front and rear overhead console controls . I will put them in the positions and there's no function of any kind .

Awesome. Thx
Please answer these three steps.
1. What's the level of your mechanical/electrical ability.
2. Find your Rear AC(blower) fuse and test if it's ok.
3. See if there's power(12VDC) on both sides of fuse

1. I don't understand this question
2 . Where is that located at ? Under the hood or side panel by the passenger side dashboard
3. How would I check that ? Do I need a digital volt machine

I can tell from your answers that it's going to be tough trying to fix your AC issues DIY because you do not seem to have any idea
of basic electrical or mechanical know how.... no insult intended. Try searching online for the location of the fuse box for your car and find out what fuse # controls the Rear AC Blower.
My car is a Suburban not a Tahoe but the ACs are very similar and yes you will need a VOM(volt ohm meter--- a needle meter works fine) to test the fuse and electrical circuits.

i do know there's a fuse box under the hood and the side panel by the dash . I'll look into it tomorrow. I saw a video where there's some kind of connection by the driver side ebrake that usually fries and kills the rear ac. There are two orange cables that are connected to them and this person spliced them n tied them together and his rear ac worked so he ran it direct .

OK.
1. Find the fuse for the Rear AC and check it if it's good
2. Check both sides of the fuse if its got power(12vdc)
3. if it does then check both wires you mentioned above if its got power
Do these checks and let me know what you find then we will move on to the next steps

Wondering if someone may be able to help me with the next step. Here’s where I am: 2000 Tahoe with automatic Front/Rear AC. Unit has two overhead controls: one front seat, one rear seat. Blower stopped working recently. Pulled rear panel, checked voltage with VOM. Have 14v at Orange/Black wire coming into the blower regulator. Voltage to smaller center wire stays consistent, whether the fan control is on low or high - no change based on controls. Reads about 1v on the Purple/Black wires that go into the blower housing. Blower runs if I provide 12v to it. Trying to determine how to isolate whether it is a control or motor regulator issue, or something else I haven’t checked. Thank you for your help!

Newbie set to reply if this account works. Stand by...

OK, account is established. My reply to the above issue might be moot if the problem has been resolved.

I recently lost my rear blower meaning no flow was coming through the headliner vents. Assuming all of your fuses are good we will proceed to step one...

Step one:
After researching many threads on this issue I pulled back the R-Rear panel to expose the blower and resistor module (many threads suggest to replace the RM as a shotgun but at $200 I ain't gonna do it). My first goal was to establish that the ORANGE WIRE on the resistor module was HOT by using a TEST LIGHT and NOT a voltmeter. (Voltmeters consume very little current and may give a false sense of proper continuity.) My ORANGE WIRE had NO voltage when I probed it with a TEST LIGHT. The ORANGE wire should be HOT with the key off. So this means that the resistor module and blower are most likely good so we move on two step two...

Step two:
I removed the driver side kick panel by the emergency brake lever to expose a few wire connectors. The large 18-20 pin connector with the THICK ORANGE wire is the area of focus. Most of the wires in that connector are 16-18ga but the ORANGE wire is 10-12ga. My connector lugs were BURNED and made momentary contact. GM undersized the lugs so bypassing the connector is necessary.

Step three:
Cut the ORANGE WIRES on both sides of the connector and splice them together with a suitable quick connector or better yet solder them and insulate. THIS SOLVED MY ISSUE OF NO REAR AC BLOWING THROUGH THE ROOF VENTS.

I discovered this fixed by surfing around so I cannot take full credit but if you have basic skills and troubleshooting techniques this should be a simple DIY project that would cost less the $3 versus $350-$500 at a shop.

Time for a beer...

Wow - sounds like the fix I found on the Internet - and did - for a 55" Mitsubishi DLP HDTV. It had overheat warning, all 3 fans were working; Mitsubishi was aware of this issue and even extended their factory warranty a year or two, but my TV was older. The heat sensor was NOT the issue, it was resistance at the harness connector. So I cut out the connector and soldered the two wires to their corresponding ends, fixed permanently.

Good for you !!!

Dude, your my hero!
 

You, sir, are a lifesaver!! Shoot me your Cash App/PayPal and I'll buy you a beer!
https://cimg3.ibsrv.net/gimg/chevrol...97bdb11b90.jpg
Orange wire burned in two at the pins under dash on driver side. Clip both sides, bypass the plug! Presto!!!!! Working rear fan!!

Great discussion here, but my 01 Yukon XL has a slightly different problem that I''m hoping to get some advice on how to troubleshoot; in my case, the orange wire is good battery voltage (even jumped with my power probe to be sure), ground is solid, but I am only getting 1.0 volts from the purple wire, not matter which (front or rear) panel I change rear fan speed at. How can I go about finding the issue with the fan speed control wire without shooting the parts cannon and replacing the control panels unnecessarily.