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2007.5 (And Up) Silverado Blower Motor Resistor

Discussion in 'The Okie Corral' started by USMCsilver, Aug 17, 2012.

  1. USMCsilver

    USMCsilver Boat Life ©

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    Anyone have to replace a blower mower resistor on their truck? If so, any pointers?

    I got in my truck today and the blower wouldn't come on. All my lights work for the controls, and you can hear the compressor engage when you turn on the A/C, but there's no fan turning.

    I see this is a pretty common problem, and watched a few YouTube videos, but none deal with my model year.

    Figured I'd check here, as I'm not a member of any Chevy forum.

    TIA. :wavey:
     
  2. .264 magnum

    .264 magnum CLM

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    Totally irrelevant but I had to replace the resistor on my MB E320 last year. For that car the resistor was buried into a board that included a new blower fan motor and some other crap. It's a nice way to sell a $0.30 part for $125, frankly it might have been more than that. It took about ten minutes to install. I'm handy but not a pro by any means.
     

  3. USMCsilver

    USMCsilver Boat Life ©

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    Dealer quoted me about $50; found it online for about 1/2 that.

    I believe it should be relatively simple and I'm going to just buy the part and skip paying them the money to hook the truck up to a diagnostics machine.

    If I replace it and still no joy, I'm just gonna go pay them whatever they want.

    No air in the brutal SC heat/humidity is not fun.

    (BTW, I've pulled about every fuse I could think of.) There are three big thingies under the hood in that fuse box that deal with the blower fan, but everything I'm reading leads me to believe it's the resistor. Guy at Chevy dealer said that's most likely the case, too.
     
  4. Jay S.

    Jay S.

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    Try SilveradoSierra.com. Should be someone in the electrical forum that can answer this question.
     
  5. vikingsoftpaw

    vikingsoftpaw DEPLORABLE ME!

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    I believe it's a standard GM part. I had the same issue with an Olds.

    Is your blower motor totally inoperative through all fan settings, or does it work on high only.

    If you have high only, it's the resistor network or the harness. (My harness connector was burned out.)

    It not, check the relay and the blower motor.
     
    Last edited: Aug 17, 2012
  6. USMCsilver

    USMCsilver Boat Life ©

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    It won't work on ANY speed.

    See the large things in the 7-8 o'clock position? Those say something about the blower... (Disregard the arrow/texts. Not my picture.)

    [​IMG]
     
    Last edited: Aug 17, 2012
  7. USMCsilver

    USMCsilver Boat Life ©

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    Those big things read in the manual as "FAN HI", "FAN LOW", "FAN CNTRL".

    I'd hate to swap out a resistor and have that not be the problem when I could just plug in one of those little things.

    I also hate to spend the money to have them hook it up to the diagnostics machine.

    I hate vehicle problems. You'd think for the money you spend... :upeyes:

    Around pages 530 you'll find the fuse boxes if you care to look:

    http://pdfcast.org/pdf/2008-chevrolet-silverado-owners-manual
     
    Last edited: Aug 17, 2012
  8. Big Bird

    Big Bird NRA Life Member

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    Funny,

    I had the same problem with my 2003 BMW 525i. I ordered the replacement part online for $119 and had it installed in 15 minutes with only one screw holding back an access panel to remove and unplug the old part and plug in the new one...
     
  9. Atlas

    Atlas transmogrifier

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    Those are relays.

    I would check if they are all the same part-number.. (which they could easily be).
    If so, buy one and swap it for each of them in turn to see if it cures the problem.

    I don't know specifically your truck's electrical system, but it's probably similar to most Chevy trucks..
    If so, then a bad resistor would leave the fan working on the highest speed but not on the lower speeds.
    That being the case and since you've checked all the fuses, one of the relay may be your answer. Be aware though that relays are pretty reliable, so I wouldn't assume it to be a relay.

    The other possibility of course is that the fan motor itself is bad.
    I would check the connectors in the harness leading to the fan motor for loose connections or burnt pins.
     
    Last edited: Aug 17, 2012
  10. USMCsilver

    USMCsilver Boat Life ©

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    Spent $53 on a new resistor today and tried it in the parking lot, as I had already removed all the crap to get to it.



    Turned the key on...











































    Not a damned thing! My wife is at the parts shop right now getting me a simple fuse tester, and I'm gonna test every damned fuse I have.



    I still think it may be one of the blower relays, but those parts weren't in stock at the dealer. In the picture above, I think it's the relay in the cluster @ 7 o'clock -- the one to the right of the clusters is my next guess. $28 for that part, but it wasn't in stock.



    They're gonna get it ordered and hook up to the diagnostics machine tomorrow. They said if it's that simple, they won't charge me for the diagnostics since I'm already out the cost of the resistor.



    So...maybe it's a relay or the blower motor is shot. Hope it's not the blower motor, because that kinda looks like tight spaces and a ***** to change out. If it's the motor itself, then I may just let them change it out.
     
  11. Hailstorm

    Hailstorm Boom Shacka

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    I would invest in a test light. Check for power. Then do the reverse and check for ground. This will tell you if it is the motor or not.

    Don't bother changing the resister if you don't have high speed. High speed bypasses the resister. You have another issue.

    You can make a test light using a light bulb and some wire.Just don't have it laying on something it can melt.
     
  12. Gareth68

    Gareth68

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    Well you just found out rule number one of vehicle repair. Replacing parts comes only after proper diagnosis.

    Otherwise it can get costly.

    Get a meter, start diagnosing.

    Are you getting power to the fan?

    If yes, then no need to look up stream.

    If no, work back to the next point in the circuit.

    Non intermittent electrical issues are usually pretty easy, if time consuming if you have a good diagram and a meter.
     
  13. Wake_jumper

    Wake_jumper

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    Sounds like the blower motor is shot. Same thing happened to my Silverado... when it was just 4 months old.
     
  14. finz50

    finz50

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    Replaced mine on a 2006 2500HD around a year ago....you may want to buy the harness when you buy the motor too....usually one or the other goes bad and if you buy them online it'll save you 50% off dealer price. Took me about 30 minutes to change both out.
     
  15. jfost11

    jfost11

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    It is a common problem on those trucks. One of my employer's company trucks did the same thing and my manager's personal truck did it as well. I'm fairly certain that I remember the problem being in the ground wire of the harness running to the blower motor. At one point wiggling the wiring brought the company truck's motor back on.
     
  16. GLWyandotte

    GLWyandotte Señor Member

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    On my '03 GMC the part was located on the inside of the cab, passenger side firewall. I yanked the part, plugged the new one in and the fan worked again.
     
  17. USMCsilver

    USMCsilver Boat Life ©

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    Well -- I dunno what the hell's going on.

    It works now. I tried it at the dealer with the key in the "on" position -- I never cranked the truck. I think I tried it again on the way home, but...it didn't work...I think...

    Anyhow -- I did some work out on the truck earlier (replaced a speaker, vacuumed, Armor All'd, etc.) and on the way back from the barn to the house, I tried it again and it worked. Off/On/Hi/Lo/Auto...etc.

    Beats the hell outta me. But I'm happy. Put in a "newish" Sirius radio on Saturday, got my speaker replaced today (which had wet connectors), and now I have A/C.

    Freakin' awesome! :)
     
  18. Atlas

    Atlas transmogrifier

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    Then you know with some degree of certainty that it isn't a bad motor.
    If it works intermittently then it probably isn't the motor.


    That leaves loose connections or the possibility of an intermittent relay.
     
  19. USMCsilver

    USMCsilver Boat Life ©

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    I did take out that one relay and took it to the part's counter.

    However, I tried the fan after I removed and replaced the relay (I think).

    Hell, like I said, I'm clueless here. I may put the old resistor back in and see if it'll still work for me. If that functions, then the answer will be that it WASN'T the resistor...

    Everything's still unbolted, so it'll be a snap to test this theory out.
     
  20. Hailstorm

    Hailstorm Boom Shacka

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    Pull the connector off the motor and look and make sure it is not melted.