blower fan problem and question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Blake_72_Blazer · 11-22-2004, 11:04 PM

Hey Guys, I need your help. I am not sure what part needs to be replaced or what needs to be fixed, but here is the issue. When I turn the fan switch (with A/C model) to first on position i can hear the blower fan bearly turning, second position blower fan turns fast enough tp push a little air out the vents, but not as fast it did last week, and the thrid position (Hi) the blower fan turns off. Is it the motor, switch, or speed resistor? Is there a way I can test each part?
Thanks in advance for your help, Blake

jhow66 · 11-22-2004, 11:05 PM

Ac?

Blake_72_Blazer · 11-22-2004, 11:12 PM

Sorry I forgot to state, with A/C.

tim_and_bobbi_blazer · 11-22-2004, 11:18 PM

Sounds like the resistor to me. You can check your motor by hooking it to 12v. If it runs full speed, it's ok. you can also take the plug off the resistor move the switch and check for voltage at the pins with a meter. If it's an AC truck, AND if memory serves, the switch has a 'triangle' shape plug. Seems like pwr came from the brown wire and went to orange, blue and yellow. you could take the plug off and use a jumper across the brown (could have been black -- don't have a print in frount of me) to the others and if the motor works, you'd have a bad switch. Let me know if you continue to have trouble.

Bobbi

tim_and_bobbi_blazer · 11-22-2004, 11:22 PM

Plain forgot about the relay. There's a relay on the far side of the pletum over on the passenger side. be sure to check it also. It can cause problems too.

Bobbi

teamharvey · 11-22-2004, 11:41 PM

I just had a similar situation. Although mine is without AC, it was a $6 resistor that caused my problem.

Bret

11-22-2004, 11:04 PM	#1
Blake_72_Blazer Registered User Join Date: Aug 2003 Location: Allen, Texas Posts: 26	blower fan problem and question Hey Guys, I need your help. I am not sure what part needs to be replaced or what needs to be fixed, but here is the issue. When I turn the fan switch (with A/C model) to first on position i can hear the blower fan bearly turning, second position blower fan turns fast enough tp push a little air out the vents, but not as fast it did last week, and the thrid position (Hi) the blower fan turns off. Is it the motor, switch, or speed resistor? Is there a way I can test each part? Thanks in advance for your help, Blake __________________ Blake 72 Blazer, 350, tubro 350, NP205, 32x11.5x15 http://home.comcast.net/~blakesara/K5Photos.htm Last edited by Blake_72_Blazer; 11-22-2004 at 11:13 PM.

11-22-2004, 11:05 PM	#2
jhow66 Registered User Join Date: Jun 2002 Location: Knoxville Tenn. Posts: 3,058	Ac? __________________ 56 Chevy Bel-Air 2dr. HT (purchased new) 71 Chevy Cheyenne SWB PU (502HO) 65 GMC short bed step--work in progress and my gofer

11-22-2004, 11:12 PM	#3
Blake_72_Blazer Registered User Join Date: Aug 2003 Location: Allen, Texas Posts: 26	Sorry I forgot to state, with A/C. __________________ Blake 72 Blazer, 350, tubro 350, NP205, 32x11.5x15 http://home.comcast.net/~blakesara/K5Photos.htm

11-22-2004, 11:41 PM	#6
teamharvey Registered User Join Date: Jul 2004 Location: Turlock, Ca Posts: 579	I just had a similar situation. Although mine is without AC, it was a $6 resistor that caused my problem. Bret __________________ 71 Custom 20 Deluxe..soon to be SWB 1/2 ton 1 incredible wife 2 great kids

11-22-2004, 11:18 PM	#4
tim_and_bobbi_blazer Registered User Join Date: Oct 2004 Location: Texas Posts: 105	Sounds like the resistor to me. You can check your motor by hooking it to 12v. If it runs full speed, it's ok. you can also take the plug off the resistor move the switch and check for voltage at the pins with a meter. If it's an AC truck, AND if memory serves, the switch has a 'triangle' shape plug. Seems like pwr came from the brown wire and went to orange, blue and yellow. you could take the plug off and use a jumper across the brown (could have been black -- don't have a print in frount of me) to the others and if the motor works, you'd have a bad switch. Let me know if you continue to have trouble. Bobbi

11-22-2004, 11:22 PM	#5
tim_and_bobbi_blazer Registered User Join Date: Oct 2004 Location: Texas Posts: 105	Plain forgot about the relay. There's a relay on the far side of the pletum over on the passenger side. be sure to check it also. It can cause problems too. Bobbi



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