Most likely reason fan isn't working? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Jobe72 · 09-03-2010, 04:29 PM

I'm about to dive into my AC/Heater system that isn't working.
The fan doesn't work and that is my first task.

Is there a more common reason why? I've checked the fuse and my wiring harness is intact.

Thanks

cdowns · 09-03-2010, 04:46 PM

sometimes the housing is filled with 40 years of crap and vermin and the fan wont turn

Lee H · 09-03-2010, 04:52 PM

Check to see if your getting power at a few points with a test light. At the fan it's self (with the switch on) at the switch (it's the brown wire). If your getting power at the fan then your fan is more than likely bad. If your getting power at the switch, check the relay.

Hottrucks · 09-03-2010, 04:56 PM

run a wire from the batery to the fan there pretty close that will proably blow your truck full of crap ;eaves and dust....but at least you'll know the fan is good.....next head down to auto zone ( where I got mine) and buy the heater/A/C fan relay its about $15 then pull your glove box and on the side of the heater box up agains the wall you'll find it....repace it!!!! its to much of a PIA to get to and not..... I bet a piece of pizza that its your issue....next would be the switch

*Shane* · 09-03-2010, 05:44 PM

HUA problem on my end ... you already said the fuse was good. Doh!

Jobe72 · 09-03-2010, 05:59 PM

Well good thing my glovebox is a mess and comes out very easily!

Thanks for the tips guys, I appreciate it.

cparman · 09-03-2010, 06:18 PM

nobody mention checking the ground side, of this system. Ask me why I would say that! Do you have power at the blower motor? do you have a ground at the motor? Confirm 12v+ at the blower switch, and move to the relay from there. Don't forget the ground side

Hottrucks · 09-03-2010, 06:34 PM

^^^ why would you say that???

cparman · 09-03-2010, 08:34 PM

been beat up more than once with a bad ground. IIR the relay and the blower motor needs to be grounded. The ground at the blower motor is a screw with a 1/4" head

Quote:

Originally Posted by Hottrucks

^^^ why would you say that???

72shortstep · 09-04-2010, 06:27 AM

Quote:

Originally Posted by cparman

nobody mention checking the ground side, of this system. Ask me why I would say that! Do you have power at the blower motor? do you have a ground at the motor? Confirm 12v+ at the blower switch, and move to the relay from there. Don't forget the ground side

I agree, this is what caused mine to stop working.

09-03-2010, 04:29 PM	#1
Jobe72 Registered User Join Date: Mar 2010 Location: Austin, TX Posts: 299	Most likely reason fan isn't working? I'm about to dive into my AC/Heater system that isn't working. The fan doesn't work and that is my first task. Is there a more common reason why? I've checked the fuse and my wiring harness is intact. Thanks __________________ 1972 GMC Sierra LWB (Aquafresh) 1962 Cadillac Convertible 1962 Cadillac Sedan project

09-03-2010, 04:46 PM	#2
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Most likely reason fan isn't working? sometimes the housing is filled with 40 years of crap and vermin and the fan wont turn __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

09-03-2010, 04:52 PM	#3
Lee H Registered User Join Date: Jun 2010 Location: Upland Ca Posts: 4,143	Re: Most likely reason fan isn't working? Check to see if your getting power at a few points with a test light. At the fan it's self (with the switch on) at the switch (it's the brown wire). If your getting power at the fan then your fan is more than likely bad. If your getting power at the switch, check the relay. __________________ 1972 C10 SWB, Air, PS, PB, 350/350THM. Second owner. 1965 Corvette roadster, 44K miles, 327/365 SHP, 4 speed, side exhaust, knockoffs, teak, second owner (bought in 1970), Have ALL numbers matching components. My frame off restoration thread: http://67-72chevytrucks.com/vboard/s...d.php?t=556703

09-03-2010, 04:56 PM	#4
Hottrucks Redefining LowBudget Join Date: Mar 2009 Location: lebanon Cow Hampshire Posts: 4,538	Re: Most likely reason fan isn't working? run a wire from the batery to the fan there pretty close that will proably blow your truck full of crap ;eaves and dust....but at least you'll know the fan is good.....next head down to auto zone ( where I got mine) and *buy* the heater/A/C fan relay its about $15 then pull your glove box and on the side of the heater box up agains the wall you'll find it....repace it!!!! its to much of a PIA to get to and not..... I bet a piece of pizza that its your issue....next would be the switch __________________ 1970 C10 CST fleetside 472 ....big dreams little cash... http://67-72chevytrucks.com/vboard/s...d.php?t=335721 SunShine Syndicate.. Mikes Sandwich Fair Run OCT 8th 2011 http://www.thesandwichfair.com/html/...auto_show.html

09-03-2010, 05:44 PM	#5
Shane Account Suspended Join Date: Jun 2000 Location: over yonder Posts: 14,270	Re: Most likely reason fan isn't working? HUA problem on my end ... you already said the fuse was good. Doh! Last edited by Shane; 09-03-2010 at 05:45 PM.

09-03-2010, 05:59 PM	#6
Jobe72 Registered User Join Date: Mar 2010 Location: Austin, TX Posts: 299	Re: Most likely reason fan isn't working? Well good thing my glovebox is a mess and comes out very easily! Thanks for the tips guys, I appreciate it. __________________ 1972 GMC Sierra LWB (Aquafresh) 1962 Cadillac Convertible 1962 Cadillac Sedan project

09-03-2010, 06:18 PM	#7
cparman sharp as a marble Join Date: Jan 2007 Location: atlantic beach,florida Posts: 1,082	Re: Most likely reason fan isn't working? nobody mention checking the ground side, of this system. Ask me why I would say that! Do you have power at the blower motor? do you have a ground at the motor? Confirm 12v+ at the blower switch, and move to the relay from there. Don't forget the ground side

09-03-2010, 06:34 PM	#8
Hottrucks Redefining LowBudget Join Date: Mar 2009 Location: lebanon Cow Hampshire Posts: 4,538	Re: Most likely reason fan isn't working? ^^^ why would you say that???

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