No A/C or Heat

doc420

Original poster
Member
Dec 8, 2011
5
I have a 2006 TBSS and about a month ago the a/c and heat stopped working. It does not come out of any of the vents. No defrost, floor, or main vents. When the SUV is driving down the road you can feel the a/c or heat, whichever is on, slightly coming out of the vents.

I've searched and found threads talking about the resister modules and fuses might need replacing. I checked the fuses and they all looked good.

I'm wondering if you guys think it's the actually blower motor going out?

Any help would be appreciated!!!
 

doc420

Original poster
Member
Dec 8, 2011
5
jham said:
When I first got my 2005 my heater and a/c stopped as well. It was the relay that had failed has worked great ever since

Since I have the Auto A/C and Heat feature on my SUV, will I need to replace the relay or resistor?

A part number would be great!
 

christo829

Member
Dec 7, 2011
507
Fairfax, Virginia
Do you have the digital or analog controls? If digital, it's most likely the control unit itself.
If you've got the analog controls, most likely the resistor pack has failed, and/or the ground lead
in the wiring connector to the resstor pack.

Good Luck!

Chris
 

doc420

Original poster
Member
Dec 8, 2011
5
christo829 said:
Do you have the digital or analog controls? If digital, it's most likely the control unit itself.
If you've got the analog controls, most likely the resistor pack has failed, and/or the ground lead
in the wiring connector to the resstor pack.

Good Luck!

Chris

It has the digital controls on it. Any recommendations for cheapest place to buy or a part number?
 

Vicompc

Member
Dec 5, 2011
109
I replaced my Auto A/C by using this site: Car-Part.com--Used Auto Parts Market
What I found was that the part is year specific and part number specific you will need to look at the back of your unit for the part number. The site lists wrecking yards that have the part and also shows pricing. I was able to purchase a replacement for $60.00 shipped off a Trailblazer that only had 38000 miles.

Make sure you have Option code CJ2, you will have one of the following part numbers:

15203179
15220319
15814152
15845093
 

Vicompc

Member
Dec 5, 2011
109
I checked E-Bay also and found the bulk of the parts are from wrecked units unless you want to pay the higher prices.
 

neelskit

Member
Dec 7, 2011
69
doc420 said:
It has the digital controls on it. Any recommendations for cheapest place to buy or a part number?

Before buying any parts, I would check that the blower motor is actually getting power. Disconnect the black/purple wire harness that is plugged into the blower motor. With the HVAC system turned on, set the control to the highest fan speed. Measure the the voltage between the black and purple wires. (black is ground) You should have ~12VDC. If you do, the motor is most likely bad. If you have no or little voltage, disconnect the 3-wire harness from the Blower Motor Control Module. Check to see that you have 12VDC between the red and black wires on that harness. (again, black is ground) If not, then fuse 35 under the hood is most likely blown. If you do have 12VDC, then either the Blower Motor Control Module or the Control Head itself is bad. The Blower Motor and Module are located behind the Glove Box. You can access them easier by removing the plastic kick panel under the dash.

Let us know what you find...
 

christo829

Member
Dec 7, 2011
507
Fairfax, Virginia
Heh....I'm apparently too reliant on the OS. Got used to where things were
there, and now can't locate information.

With the digital controls, there's a speed control module instead of the resistor
pack, and there's one component (A hexfet, I believe) that seems to fail more
commonly than the blower motor itself.

I second neelskit's recommendation regarding checking for power at the motor
connection. This will also give you a chance to inspect the speed controller and
connector. Overheating could cause a wiring failure.

Are you handy with a multimeter and/or a soldering iron? If I can locate
the relevant info, I'll pass along the part number of the component. I'll look
for that and the speed control module number as soon as I get this next map
project off my desk.

Cheers-

Chris
 

neelskit

Member
Dec 7, 2011
69
christo829 said:
Heh....With the digital controls, there's a speed control module instead of the resistor
pack, and there's one component (A hexfet, I believe) that seems to fail more
commonly than the blower motor itself...

...Are you handy with a multimeter and/or a soldering iron? If I can locate
the relevant info, I'll pass along the part number of the component...

Hope this saves you some time- here is component:
Digi-Key - IRF1405LPBF-ND (Manufacturer - IRF1405LPBF)
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
No. That's for the manual controls.
 

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