I have a 2006 Silverado LT3 with Auto A/C and my blower runs with key off. Did replacing the BCM fix that problem on your vehicle?

Nordeast4 Same vehicle, same problem. So for clarity, what did you replace, the blower control module?

I just replaced the fuse that controls the blower with two wires ran to a toggle switch I installed up front. Yes, my fan is stuck on high, but at least I can turn the fan off when I leave the vehicle or don't want it on anymore.

kzfaq.info/get/bejne/rtR5d8hhz5mqomg.html

Mine is doing the same. I have to unhook the battery to get the fan to quit.

That's about the gist of it. In automotive systems many actuators and controls are switched through the ground.

+mapoint48 There's only 3 wires. Black to Black, Red to Red for the big wires. The color of the remaining small wires doesn't matter but they get spliced together.

sorry I meant to say a blower motor module has been replaced 3 times today

check the description

Blower quit.

Sounds like a really funky electrical issue. Sounds like the actuators are acting up though but I don't know why the throttle would affect it.

Actuator issue, I have a video on that too.

Low air flow can be a restriction in the vent system or slow blower speed. You can hear if the blower is spinning at full speed if its not either the motor is failing or there is trouble somehwere in the wiring/ module. Proper diagnostics is the only way to know or sure.

HVAC module most likely. My dad's defaults to defrost only after about 2 hours, power cycling fixes it.

Did you ever get this figured out?

Sounds like a dead mode actuator

Blower working?

+Chester Cook Its the 4th one back.

Make sure you're testing it porperly. If so test for a signal at the back of the climate control module, this will take the wiring out of the equation. If there is still no signal then you will need a new or used climate control module.

I agree will really help out alot

It's different for every vehicle. The colors of wires vary from vehicle to vehicle.

Yeah, that's exactly what I need to know. The old resister has three wires and the new one has six or seven. How do they splice?

Really and the part number

@@ojibwayinca8487 do u know that part number

It's probably shorting out or the bearings are failing, both will cause it to draw too much power. If it has full power while spinning but is still doing that then its on it's way out.

I'm not familiar with the terrain, its a completely different platform. You may have issues with the controls or issues with the actuators, but with all those symptoms it sound like the climate controls are going out.

Electrical issue. Something gets hot and fails. Or its overheating and the PCM is shutting it down to protect the engine.

Blow motor control module can kill the battery, but unlikely to do so that fast. I would fix that first then worry about the actuators.

I’ll give it a go and then report back! Thanks!

kzfaq.info/get/bejne/rtR5d8hhz5mqomg.html

The new Blower control module has a different connector from the old one, so you have to splice the new connector on. Its just two big power wires and then the signal wire. Black to black, red to red, then match up the two small wires.

It's your HVAC mode actuator,it's a common issue on GM vehicles,another symptom would be a clicking noise/stripped gear ,there's like 4 upfront,when they click,or go bad,they're a little easier to find,because you can see/feel it clicking,when the motor goes bad you won't see the outer hole move,when you go throught the cycles like defrost,to dash air,to foot,the individual climate controls are usually the 2 fronts,1 passenger side,1 driver.Go check out a couple of vids on HVAC mode actuators ,and also do the same search so you can locate them,and find out what each one controls,it's a real easy fix,also find out where you HVAC fuse is and pull it for like 10seconds,then put it back,when you start the car let the air run for atleast 90sec to allow the HVAC system to recalibrate! $40-60 for 1 do it urself,or $200 at the dealer for 1with installation.I say go with the 1st option!LOL

Thank you. I'm thinking you've nailed it as I can indeed hear the clicking sound that you are describing. It sounds like the clicking is directly under the driver side dash/instrument cluster. Thanks again. Much appreciated.

Sounds like an actuator issue but I'm not sure where that would be.

Blower motor might be drawing too much current. Check the fuse for the blower motor and make sure its the correct amperage.

I've been reading through the comments and Darrin Mccullough stated above " +pfun41 Thank you for pointing me in the right direction! I got it working last night by replacing the transistor (mosfit) inside the control module. Turns out this is like a mini VFD like they use on industrial motors. Some people had said they replace the blower motor at the same time because it going bad can draw more amps and make the controller fail prematurely. Have you experianced this at all?" So it could be your blower motor drawing too many amps thru the controller burning up the MOSFET transistor/ The metal-oxide-semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is a type of field-effect transistor (FET), most commonly fabricated by the controlled oxidation of silicon. It has an insulated gate, whose voltage determines the conductivity of the device. This ability to change conductivity with the amount of applied voltage can be used for amplifying or switching electronic signals. (MOSFET definition from en.wikipedia.org/wiki/MOSFET) If I were you I'd remove and replace that fan or replace it's brushes and bearings with a good cleaning. Good luck.

If its the blower that doesn't work and it happens with both ac and heat then most likely it is the blower control module or the climate control module.

OK thank you and what Fies the climate control module look like?

Its the piece with the buttons and knobs and the lcd display.

Theoretically yes but I believe you would have to rewire it for a blower resistor instead of a blower control module.

@@pfun41 Thanks for pointing that out. My problem with the digital control unit is that it only starts heating at maximum setting... ? Calibrating didn't help...

Sounds like a problem with the climate control module. It could also be an issue with the power to the climate control module. Test the climate control module for power the next time it happens. You'll need to find a connector pinout for it.

I did replace the climate control module and the problem cleared up.

Could be a motor, control module, or blower control module. Have test the blower control module and blower motor in the back. Not sure where exactly, Ive never worked on one of those.

+pfun41 actually I did just have the blower motor replaced still did the same thing (used it very very few times but this time the switch doesn't do anything neither the rear fan controls either so yup it's gotta be the module and unfortunately it has to be dealer ordered and I heard it could run about $200 :(

+pfun41 and unfortunately I have not seen anything online about a control module for the rear... only for the front console

It has to have one to control power to the blower motor. I would suspect they used the same unit as the front to save costs. Might be worth pulling the panel off and trying to find it yourself.

maybe possible seeing as thought with the front unit active, the back fan turns on while the rear vents are shut

+anas AL - Jamal no, it's buried in there.

+pfun41 OK thank you

If you're talking about the EXT models those have a separate HVAC system in the rear. If the front doesnt have air blowing it could be a blower control module or a blower motor. In which case this applies.

i.mi

I never replaced the blower.

+bryon clemons nope

Why?

Check for voltage where the wire exits the back of the climate control module, that will rule out a wiring issue.

Thank you , i did and i have no voltage. Does that mean my climate control is bad ?

If you have no voltage at all even with the fan on high then yes, the climate control module has failed.Robert Aratari

Patsy Stott blower motor resistor

@@fearnofish8537 . yes, I read earlier that the resistor module has a relay built into it that causes that as they go bad.

+Darin Mccullough A bad ground for the climate control module would result in various strange behavior or no power. Weak grounds cause all sorts of inexplicable behavior especially with computerized components. A complete open ground would result in a dead climate control system. I'm not sure why you suspect an open ground. You know there is not enough voltage getting to the motor when the symptoms occur, now you just need to know if the module is getting proper power and signal under the same circumstances.

+pfun41 Thank you for the reply. I have proper voltage at motor on the positive wire at all times. Whats throwing me off is when the motor doesn't turn I have that voltage on the motor ground wire. Just a sec ago I thought screw it and jumped the motor ground wire to chassis ground when fan wouldn't run and it started working fine if take that off it works until I start playing with speed controls then quits if I tap the - lead on ground again it will repeat this cycle. I don't have much DC experience and its throwing me for a loop. If on a 120VAC circuit working voltage past the load on neutral (ground) would most likely be open neutral. I really appreciate your help I dont have a lot of money to go buy components until I know for sure whats broken.

+pfun41 I think I got it so the controller sends voltage to the motor at all times then pulses the ground through a transistor. Some where in the controller this is a bad connection hence why when I jumper it to ground it works until I try playing with the speed control. If this seams legit enough I think ill cut the controller open tonight and see if I can find a bad connection to solder or a transistor to replace.

+Darin Mccullough Ok, let me try to explain this. Forget everything about AC. The blower control module is basically like a giant variable relay. It has it's own 12v power supply (positive and negative) and feeds variable voltage to the blower motor based on a signal it recieves from the HVAC module over the single small wire. I am not familiar with the internal circuitry of the blower control module, but it doesn't matter. All you need to know is that 12 volts goes in, and (based on a signal from the HVAC module) a voltage from 0-12 volts goes out to the blower motor. At around 5:20 I showed how to check for a signal from the HVAC module. What you want to do is backprobe the small signal wire and the red positive wire and leave the connector plugged in to the Blower control module. Rig it up so you don't have to hold anything and can see the meter from the driver seat. I use T pins and test leads. This way you can monitor the signal while the system is operating. You'll need to just drive it like this until it acts up again, there is no other accurate way to diagnose it. When the issue finally occurs again, note what voltage you are reading. If you aren't getting a voltage that changes with the fan speed then the HVAC module has failed. Just to be shure, pull over and unplug the connector, leaving the meter connected, if nothing changes then you can be shure it's the HVAC module.

+pfun41 Thank you for pointing me in the right direction! I got it working last night by replacing the transistor (mosfit) inside the control module. Turns out this is like a mini VFD like they use on industrial motors. Some people had said they replace the blower motor at the same time because it going bad can draw more amps and make the controller fail prematurely. Have you experianced this at all?

Jake Sosinski Put the fuse back in so the blower is running. Then test for a signal from the blower control module with the car OFF. If you're getting a signal then there is a problem with the climate control module. If not, then the blower control module has shorted. Only testing will confirm but I bet it's the blower control module, it handles alot of current and failure is common.

Okay thanks a lot man

not

+bryon clemons nope, never seen one with an adjustable gas and brake.

If you have 12 volts or thereabouts at the Blower motor and it's not running then your blower motor is bad.

i bought one from O'Reillys...and still does not work... going to go exchange it in morning, hopefully it was a faulty new blower motor... thanks for the help

I ended up testing my old blower fan on the car battery...It does work... What else could I check to see why system does not work? another thing is that I drove to work with the blower fan not hooked up and sitting on the floor board, had the heat set to 90, and never could feel heated air blow from the hole where the fan get mounted in. I am now thinking that no blower fan and the heat are related. Thank you for any help that you can offer me.

The blower is what moves air around in the HVAC system, you will not feel any air moving with it removed. Plug everything in and leave the motor sitting on the floorboard and see if it will spin when you turn the fan on.(don't do this for long, the blower control module needs airflow to stay cool) Its possible there is something catching on the fan when it is installed and keeping it from turning. Sometimes Blower motors can fail in such a way that they won't start spinning again if they stop in a certain position, moving the fan a little will make them start working again temporarily. It's possible that your Motor has failed this way and the Oriellys unit was faulty.

What this Moron is not telling you is that these have 12volts at all times the blower module controls the ground to vary the speed. I personally check the power and ground separately so there is no confusion. So if you check it the way Moron41 says to and there is a bad ground going to the module you're going to not get the correct diagnoses . I also have found that the body ground wire gets loose and can cause these modules to go bad. The body ground is located about six inches from the battery it's the black wire bolted to inside of left inner fender.

Something funky in the hvac actuators or the climate control module. kzfaq.info/get/bejne/rtR5d8hhz5mqomg.html

Thank you...

kzfaq.info/get/bejne/rtR5d8hhz5mqomg.html

I replace blower motor and resistor and it still doesn't work can anybody help

Replace blower motor and resistor and it still doesn't work any ideas

Could be main power issue, could be a signal issue from the HVAC module, could be a loose wire. Trying to fix it without testing anything is like trying to shoot a bat at midnight while blindfolded.

Blend door actuator for the driver side failed when he reconnected the battery.

You're like the 15th person to say that, and the 15th person to be completely wrong. There's an entirely different video about that issue, I even linked it.

Blend door actuators.

Exactly what they told me at the parts store ,thanks you.

What other diagnostics have you done? How old is the battery? What makes you think its the HVAC system causing it?

Different issue, check my HVAC actuator video

Ok. Thx

Temperature actuator for driver side.

+Celeste Padilla ACDELCO 1581773

+pfun41 thank you..

Very true!

Vincent Akpan