Does your blower motor always blow? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

hilljack · 12-30-2004, 02:31 AM

In my 74 when I have the fan in the low position and the selector switch in the off position, I can still hear my fan blowing at low speed. I was just wondering if maybe the selector switch is what actually turns the fan off and possibly not functioning or is this normal?

Thanks!

r0lf- · 12-30-2004, 04:21 AM

Mine does that too. I dunno if it completely turns off or not. I just dont worry about it. :p

TIMSPEED · 12-30-2004, 05:22 AM

Yep, that's right. When my key is in the ACC position, the blower motor runs...never understood why, but I guess they did.

Blue Beard · 12-30-2004, 07:46 AM

My guess would be the switch is bad, have a 81 that does that and if I move the switch it shuts off.

76bonanza · 12-30-2004, 08:37 AM

Everyone I have ever owned has done it it is the way they are made. I wired in a toggle switch to shut it off in the summer.

Mike76251 · 12-30-2004, 09:29 AM

My '84 fan runs all the time unless the selector is in the off position.......then it shuts off.
I shut it off all the time 'cause it saves alot of dusting inside should I have to go through a dust cloud or something.

KShortell · 12-30-2004, 12:21 PM

Quote:

Originally Posted by hilljack

In my 74 when I have the fan in the low position and the selector switch in the off position, I can still hear my fan blowing at low speed. I was just wondering if maybe the selector switch is what actually turns the fan off and possibly not functioning or is this normal?

Thanks!

On earlier and non-A/C trucks, this is normal. By the mid-80s, A/C-equipped trucks like mine have the fan actually off with the selector in the "Off" position.

cliffsta · 12-30-2004, 01:20 PM

I don't get why the fan speed switch, when all the way down, still blows. Then low mark is blows Mid power, the hi mark it blows full on hard, then all the way up it doesn't blow....

**Captkaos** · 12-30-2004, 03:37 PM

As stated above, if you don't have AC, it always blows, this was part of the Flow-through power ventilation system.

**76sierraclassic** · 12-30-2004, 03:41 PM

Quote:

Originally Posted by cliffsta

I don't get why the fan speed switch, when all the way down, still blows. Then low mark is blows Mid power, the hi mark it blows full on hard, then all the way up it doesn't blow....

As stated above, it's supposed to blow all the time. It's a "safety" thing allowing "fresh" air into the cab all the time even while just idling. However, it's not supposed to work like cliffsta's does....

Mike

Slonaker · 12-30-2004, 06:01 PM

Quote:

Originally Posted by cliffsta

...the hi mark it blows full on hard, then all the way up it doesn't blow....

If yopur highest position does not blow, check the plug on the wiring harness above one of the valve covers. The high position has its own power lead, and they tend to burn up the connector over the valve cover over time.

Slonaker

cliffsta · 12-30-2004, 06:18 PM

lol oy my truck. I wouldn't be lying when i say its a one-off.....

Ill add it to the dumb things i like about my truck, like how its a Custum Deluxe but its spec'd with Cheyenne or Bonanaza options...

hilljack · 12-30-2004, 09:40 PM

Cool thanks guys, my truck is AC but probably just the same unless fan power goes through the selector switch on a 74 with AC????? Now on to the next problem, see ya in my next posts

1976K5CHALET · 12-30-2004, 11:12 PM

On my 79 i got a hvac control head out of a mid to late 80's burb with the pigtails...there was one wire difference i remember right as it's been two years or better...but after i installed the newer panel and wired it in the fan stays off in off.

DW

NeCrOmAnCeR · 12-31-2004, 12:52 AM

Quote:

Originally Posted by cliffsta

. . . the hi mark it blows full on hard, then all the way up it doesn't blow....

As stated before, check the connection above the passenger valve cover area, and also, the high (all the way up/ Max cool ) use a relay located on the evaporator box in the engine compartment. Check the relay too.

Mike76251 · 12-31-2004, 12:14 PM

The real strange thing is WHY it is a safety issue for the fan to blow all the time.
It's like Chevy expected the exhaust to leak forever or something!

12-30-2004, 02:31 AM	#1
hilljack Registered User Join Date: Nov 2002 Posts: 27	Does your blower motor always blow? In my 74 when I have the fan in the low position and the selector switch in the off position, I can still hear my fan blowing at low speed. I was just wondering if maybe the selector switch is what actually turns the fan off and possibly not functioning or is this normal? Thanks!

12-30-2004, 04:21 AM	#2
r0lf- Hotwheels? Join Date: Dec 2002 Location: Pleasant Hill, CA Posts: 1,145	Mine does that too. I dunno if it completely turns off or not. I just dont worry about it. :p __________________ 1978 Money Pit - CUSTOM DELUXE!!!!

12-30-2004, 05:22 AM	#3
TIMSPEED Join Date: Jan 2003 Location: Modesto, CA Posts: 1,321	Yep, that's right. When my key is in the ACC position, the blower motor runs...never understood why, but I guess they did. __________________ I have a few cars... See Them Here

12-30-2004, 07:46 AM	#4
Blue Beard Registered User Join Date: Jan 2003 Location: Washington State Posts: 8,834	My guess would be the switch is bad, have a 81 that does that and if I move the switch it shuts off. __________________ 1970 Chev CST 2003 Harley Fatboy 1975 Chevrolet Step Van 1956 Chev Bel Air 1977 Blazer 2WD For Sale $3000.00 1978 Blazer 2WD For Sale $7000.00 1978 Silverado 2005 Monte Carlo

12-30-2004, 08:37 AM	#5
76bonanza Senior Member Join Date: Mar 2003 Location: St robert Mo Posts: 2,001	Everyone I have ever owned has done it it is the way they are made. I wired in a toggle switch to shut it off in the summer. __________________ 1968 c10 lowered 3" 4" 355/Th400 built by Hatfield racing in joplin MO

12-30-2004, 09:29 AM	#6
Mike76251 Senior Member Join Date: Mar 2003 Posts: 2,500	My '84 fan runs all the time unless the selector is in the off position.......then it shuts off. I shut it off all the time 'cause it saves alot of dusting inside should I have to go through a dust cloud or something.

12-30-2004, 01:20 PM	#8
cliffsta Stepsides RULE Join Date: Jul 2004 Location: Pineville, LA Posts: 1,921	I don't get why the fan speed switch, when all the way down, still blows. Then low mark is blows Mid power, the hi mark it blows full on hard, then all the way up it doesn't blow.... __________________ 1981 Chevy C10 Custom Deluxe Stepside 350 V8, headers, side exhausts, 3-speed auto SOLD 1980 Chevy C10 Custum Deluxe Stepside 305 V8, Edelbrock Performer Intake, Edelbrock 1406 600CFM 4-barrel, TH350C. Bent rod. SOLD 1984 GMC Sierra Classic Longbed 6.2L Diesel SOLD 2009 Kawasaki KLX-250S too many mods for this signature 1999 Honda Accord EX 4-cylinder, 17" Motegi Wheels 215/45/17 Sumitomo tires, Tein S-Tech lowering springs, KYB GR2 shocks, Acura TL 20mm rear swaybar, debadged, blackhoused headlights, Short-Ram Intake Cardomain of the Accord

12-30-2004, 03:37 PM	#9
Captkaos www.73-87chevytrucks.com Join Date: Dec 1999 Location: Birmingham, AL Posts: 6,935	As stated above, if you don't have AC, it always blows, this was part of the Flow-through power ventilation system. __________________ Chris Lucas 1973 Chevy C-10 1978 GMC Jimmy (2WD) - SOLD 1987 R10 twin turbo LS 1991 R3500 SRW CrewCab 1985 K5 diesel swapped project 1989 K5 2WD conversion w/ Vette susp Project Captkaos Customs 73-87chevytrucks.com

12-30-2004, 06:18 PM	#12
cliffsta Stepsides RULE Join Date: Jul 2004 Location: Pineville, LA Posts: 1,921	lol oy my truck. I wouldn't be lying when i say its a one-off..... Ill add it to the dumb things i like about my truck, like how its a Custum Deluxe but its spec'd with Cheyenne or Bonanaza options... __________________ 1981 Chevy C10 Custom Deluxe Stepside 350 V8, headers, side exhausts, 3-speed auto SOLD 1980 Chevy C10 Custum Deluxe Stepside 305 V8, Edelbrock Performer Intake, Edelbrock 1406 600CFM 4-barrel, TH350C. Bent rod. SOLD 1984 GMC Sierra Classic Longbed 6.2L Diesel SOLD 2009 Kawasaki KLX-250S too many mods for this signature 1999 Honda Accord EX 4-cylinder, 17" Motegi Wheels 215/45/17 Sumitomo tires, Tein S-Tech lowering springs, KYB GR2 shocks, Acura TL 20mm rear swaybar, debadged, blackhoused headlights, Short-Ram Intake Cardomain of the Accord

12-30-2004, 09:40 PM	#13
hilljack Registered User Join Date: Nov 2002 Posts: 27	Cool thanks guys, my truck is AC but probably just the same unless fan power goes through the selector switch on a 74 with AC????? Now on to the next problem, see ya in my next posts

12-30-2004, 11:12 PM	#14
1976K5CHALET Senior Member Join Date: Jan 2003 Location: Grand Junction, Colorado Posts: 611	On my 79 i got a hvac control head out of a mid to late 80's burb with the pigtails...there was one wire difference i remember right as it's been two years or better...but after i installed the newer panel and wired it in the fan stays off in off. DW __________________ Doug Wright aka K5NUTT over @coloradok5.com Owner of http://groups.yahoo.com/group/ChevyK5BlazerChalets Certified K5 Nut

12-31-2004, 12:14 PM	#16
Mike76251 Senior Member Join Date: Mar 2003 Posts: 2,500	The real strange thing is WHY it is a safety issue for the fan to blow all the time. It's like Chevy expected the exhaust to leak forever or something!



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.