Chevy Suburban Heater Fan

[jollymon]

I have 2003 suburban. The heater/AC fan will not shut off or change speed. I had to pull tthe fuse to shut it off. Does any one have any idea what the problem is. I am sick of taking the truck to the dealer. Every time I do, a week later it is back for a new problem. Last week I had to have the drivers window fixed, now this!!!!

 

[troypolla]

Re: Chevy Suburban Heater Fan

Sounds like they made you truck before lunch or on a Monday, or a Friday. I had an older s-10 that had many problems like this. If one of my fuses blew then they would all start to blow and things would go bad quick. Check the fuses, and make sure that they are all good, and the right size.

 

[Xcusme]

Re: Chevy Suburban Heater Fan

From the circuit print, there's a relay on the motor speed control board. Motor speed is controlled by resistors in series thru single throw ,double pole relay. If the relay contacts are fused in High speed position, you'll have no speed control, only high speed fan operation......replace Blower Motor Resistor Assembly.

 

[dolluper]

Re: Chevy Suburban Heater Fan

A little more info may help>>> overhead controls or dash controls....digital display touchpad or slider manual
Engine size?
From what you discribe,sounds like an open shorted switch or bad ground, manual ones replace or repair ground,digital>> circuit board inspect for cracks in circuits if your lucky you may be able to re solder to complete circuit

 

[jollymon]

Re: Chevy Suburban Heater Fan

Thansk for the replies.

It is dash control, rotary switch with 0-4 postions.

If it is the Blower Motor Resistor Asembly, where is it located and can I test it? Should I be able to replace it myself? and the 2 most important questions, Where Can I get one and any idea how much? Thansk again for the quick replies.

Also I forgot to mention, That when I shut the truck off, the blower kept running.

Scott

 

[Boomyal]

Re: Chevy Suburban Heater Fan

Might be time to trade it for a new stretched Expedition, jollymon.

 

[jollymon]

Re: Chevy Suburban Heater Fan

Boomyal,

Damm how did my wife get on this board. No wait if it was my wife, she would have said Escort not an Expedition!!!!

 

[Boomyal]

Re: Chevy Suburban Heater Fan

Boomyal,

Damm how did my wife get on this board. No wait if it was my wife, she would have said Escort not an Expedition!!!!

It is true jollymon, the gals simply do not understand the need for BIG toys!8)

 

[Xcusme]

Re: Chevy Suburban Heater Fan

Thansk for the replies.

It is dash control, rotary switch with 0-4 postions.

If it is the Blower Motor Resistor Asembly, where is it located and can I test it? Should I be able to replace it myself? and the 2 most important questions, Where Can I get one and any idea how much? Thansk again for the quick replies.

Also I forgot to mention, That when I shut the truck off, the blower kept running.

Scott

That resistor/speed control board is usually in the air duct near the fan. It should have a wire connector or short pigtail attached and mounted with a couple of screws to hold it in the air stream. The resistor board (PCB with heavy circuit traces) has to be cooled by the air passing over it. Many of these boards have a fusible link incorporated into the circuit trace as aditional over current protection. The modules are usually potted and can't be easily repaired. Cost would be in the 30-75 dollar range and is easily swapped out.

 

[tommays]

Re: Chevy Suburban Heater Fan

The speed board was changed on the 2003 to one that does not break i saw what my old one looked like when it failed and the new one has the BEEF



Tommays

 

[Boomyal]

Re: Chevy Suburban Heater Fan

Don't forget to work on the inoperative driving lite! I swear, every 2000 and later Suburban/Tahoe I see has one burned out.

 

[jollymon]

Re: Chevy Suburban Heater Fan

OK, this gets even stranger. Because the fan would not shut off even with the truck shutoff, and the keys out, I pulled the fan labeled blower. It was in the fuse panel under the hood. That shut the fan off.

Last night coming home, out of habit, i reached down to turn the fan on, when it got to number 3 on the rotary switch, the fan came on. It only works on that one speed buthow does it work if the fuse is out????

I hate electronics!!!! Today, I am going to call the dealer and see if I can get the Blower Motor Resistor Asembly. Hopefully I can get it and replace it today.

Were taking our daughter to an achery tournament in Virgina tommorow, and it could be a long drive with the heater acting up.

Again thanks for all of the info.

Boomyal, I thought replacing the driving light was one of those regular maintenance things, you know like filly in the washer fluids, and changing the oil. It has to be done as often!

 

[dolluper]

Re: Chevy Suburban Heater Fan

Hummm>under the hood you pulled what you call a fuse.funny looking one eh! five pins square.....If so that's the HVAC blower relay not the fuse.....That's why the fan works fuse is inside the vehicle fuse box.

 

[jollymon]

Re: Chevy Suburban Heater Fan

Dolluper,

Nope, not the relay, 40amp fuse, about 1/4" square, 1" long 2 pins. The diagram on the fuse block, labels it blower. There is a A/C relay in the same block. Either way, it stops the fan from running full speed all of the time. And I mean oll of the time, car on or not.

Scott

 

[dolluper]

Re: Chevy Suburban Heater Fan

Still sounds like a shorted switch>pull connector off switch and test resistance in each different switch position with an Ohem meter, look for burn flash check ground.

 

[xtraham]

Re: Chevy Suburban Heater Fan

un-plug the heater motor resistor, (located in the blower motor plenum) if the blower motor stops when un-plugged that is more than likely the problem, but normally when a resistor goes bad you will lose only a speed setting, the high speed (max) normally is 12 volts directly from the hvac control unit switch, "the resistor IS the most common problems with gm and dodge blower motors"

 

[jollymon]

Re: Chevy Suburban Heater Fan

Xcusme hit the nail on the head. I picked up a new Blower Motor Resistor Assembly, and as soon as I pulled the old one out, I could see that was the problem. All charred and flaky. Replace and all is well.

Thank You for saving about $200 at the dealer.

Scott

 

[Xcusme]

Re: Chevy Suburban Heater Fan

Yup....d