blower motor problems narrowed down - The 1947 - Present Chevrolet & GMC Truck Message Board Network

crackajacka · 11-13-2003, 02:18 AM

ok i hooked the battery straight to the blower motor and it blows like no ones business. so i looked and the switch all it does is connect to that silverish module on the side of the a/c unit what is that called and how much is it to replace?

**crossy** · 11-13-2003, 02:33 AM

generally it's the switch in the heat control thats bad . you can do a simple continuity check on that or just jump wire past it to see if 12V is coming that far. There is also a fat wire(orange?purple?) that runs to the blower motors for the high speed because that is almost direct. (no resistance) just passes through the switch. DAVE

crackajacka · 11-13-2003, 02:40 AM

are u talking about the one wire that plugs into the blower motor?

**crossy** · 11-13-2003, 03:08 AM

yes, it passes from the switch inside to a resistor bank for the lower speeds but high speed is direct. sometimes when the resistor block goes bad you will still have high speed. if the switch is bad you won't have anything. Check fuses? .DAVE

crackajacka · 11-13-2003, 03:13 AM

well i had high for about 45 minutes then i had nothing

**crossy** · 11-13-2003, 03:29 AM

sounds like it took the fuse out at that point?

crackajacka · 11-13-2003, 03:33 AM

all the fuses in the fuse panel are ok they are all new

71-longbed · 11-13-2003, 08:13 AM

after i put my new blower in ..it wouldnt work until i put a fuse in the air cond and the heater slot .... worth a try

jimfulco · 11-13-2003, 10:57 PM

The connector lugs on the blower relay (the little silver box) and on the resistor on my Sub are prone to corrosion, so every year I have to clean them (or at least wiggle them) before the heat will blow. The contacts inside the relay also are a bit finicky, & when they don't conduct, nothing blows. Sometimes a good thump on the cover will fix it for a while.

1985K10 · 11-13-2003, 11:34 PM

My dads 98 Silverado lost everything but High. He changed the resistor block and it was cured...for a month or so, now only high works again.
If you have nothing at all id try bypassing the switch to see if its bad.

*mike reeh* · 11-14-2003, 10:26 PM

i would have to disagree, its almost never the interior switch :/ in my experiences anyways..

but yeah its probably the relay thats giving you problems..

jimfulco hit the nail on the head when he said they are finicky and prone to corrosion.. The resistor tends to rust and then disintegrate also, so I would replace them both.. they're not expensive. If you still cant get it working, let us know and we'll get it straightened out, the circuit is really quite simple

mike

crackajacka · 11-15-2003, 02:50 AM

ok whats do i need to ask for at the parts store when i go to get another resistor.

*mike reeh* · 11-15-2003, 06:09 AM

blower motor resistor and blower motor relay

mike

**N2TRUX** · 11-15-2003, 11:28 AM

Quote:

Originally posted by crackajacka
ok whats do i need to ask for at the parts store when i go to get another resistor.

I suggest you take your old one in and show it to them. That might save you a couple of trips.

Everytime I go to the parts store without the old part, I get to go back for the correct part. Sometimes twice...

**crossy** · 11-15-2003, 01:24 PM

Ken's right , even with the carb number in hand i was not able to come home with the right choke parts for my 85 the first time.
They have superceeded many part numbers into one more 'generic' number for old vehicles such as ours.. DAVE

jimfulco · 11-16-2003, 01:03 AM

It just occurred to me that sometimes the function switch (heat, defrost, etc.) on mine has to be in exactly the right place for the fan to blow. Give everything a wiggle before you drop a bunch of cash.

crackajacka · 11-16-2003, 01:30 AM

well its the resistor thing, i can pull the plug then jump the connections with a piece of wire and select high,med,low,lowlow and connect 2 ports and it blows on that setting

crackajacka · 11-16-2003, 09:26 PM

still not blowing grrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr, replaced the resistor and still nothing? what do i need to check next? n how

apstguy · 11-18-2003, 02:12 AM

The blower switch. Have you used a multi-meter and checked all the wires?

suburbasaurus · 11-19-2003, 05:14 PM

i dont know if i understand the problem here but the switch in the dash sends power to the high speed relay "little silver box on side of the a/c box" if you have power there the dash switch is good. the high speed relay is the problem if you jumped the curcits and it blows. you can get one at any parts store for $15 or less. we sell them at O'Reilly's for under $15.00. the problem with my burb was it wouldnt work on high. pulled one off another truck and it works fine now. good luck and hope this helps!

11-13-2003, 02:18 AM	#1
crackajacka Stylin Join Date: Sep 2001 Location: Tuttle, OK Posts: 620	blower motor problems narrowed down ok i hooked the battery straight to the blower motor and it blows like no ones business. so i looked and the switch all it does is connect to that silverish module on the side of the a/c unit what is that called and how much is it to replace? __________________ Ive been traveling for some time, with my fishin pole and my bottle of shyne. Most Girls like finished products and just dont understand what a good addiction does for you http://www.paulwall.us/

11-13-2003, 02:33 AM	#2
crossy Oh,you can't buy that new Join Date: Apr 2000 Location: Pennsville,N.J. 08070, USA Posts: 2,039	generally it's the switch in the heat control thats bad . you can do a simple continuity check on that or just jump wire past it to see if 12V is coming that far. There is also a fat wire(orange?purple?) that runs to the blower motors for the high speed because that is almost direct. (no resistance) just passes through the switch. DAVE __________________ "been there, done that, ruined the T-shirt". 2007 LBZ GMC Sierra, ECSB 2006 LM7 RCSB Silverado 98 Vortec project. 94,3500,6.5L 4L80 81 SWB GMC POS finally gone 73 Pinto, stock, w/CragarSS's-eww LOTS of Cummins trucks.

11-13-2003, 02:40 AM	#3
crackajacka Stylin Join Date: Sep 2001 Location: Tuttle, OK Posts: 620	are u talking about the one wire that plugs into the blower motor? __________________ Ive been traveling for some time, with my fishin pole and my bottle of shyne. Most Girls like finished products and just dont understand what a good addiction does for you http://www.paulwall.us/

11-13-2003, 03:08 AM	#4
crossy Oh,you can't buy that new Join Date: Apr 2000 Location: Pennsville,N.J. 08070, USA Posts: 2,039	yes, it passes from the switch inside to a resistor bank for the lower speeds but high speed is direct. sometimes when the resistor block goes bad you will still have high speed. if the switch is bad you won't have anything. Check fuses? .DAVE __________________ "been there, done that, ruined the T-shirt". 2007 LBZ GMC Sierra, ECSB 2006 LM7 RCSB Silverado 98 Vortec project. 94,3500,6.5L 4L80 81 SWB GMC POS finally gone 73 Pinto, stock, w/CragarSS's-eww LOTS of Cummins trucks.

11-13-2003, 03:13 AM	#5
crackajacka Stylin Join Date: Sep 2001 Location: Tuttle, OK Posts: 620	well i had high for about 45 minutes then i had nothing __________________ Ive been traveling for some time, with my fishin pole and my bottle of shyne. Most Girls like finished products and just dont understand what a good addiction does for you http://www.paulwall.us/

11-13-2003, 03:29 AM	#6
crossy Oh,you can't buy that new Join Date: Apr 2000 Location: Pennsville,N.J. 08070, USA Posts: 2,039	sounds like it took the fuse out at that point? __________________ "been there, done that, ruined the T-shirt". 2007 LBZ GMC Sierra, ECSB 2006 LM7 RCSB Silverado 98 Vortec project. 94,3500,6.5L 4L80 81 SWB GMC POS finally gone 73 Pinto, stock, w/CragarSS's-eww LOTS of Cummins trucks.

11-13-2003, 03:33 AM	#7
crackajacka Stylin Join Date: Sep 2001 Location: Tuttle, OK Posts: 620	all the fuses in the fuse panel are ok they are all new __________________ Ive been traveling for some time, with my fishin pole and my bottle of shyne. Most Girls like finished products and just dont understand what a good addiction does for you http://www.paulwall.us/

11-13-2003, 08:13 AM	#8
71-longbed Its Magically Delicious Join Date: Jan 2003 Location: oregon Posts: 2,398	after i put my new blower in ..it wouldnt work until i put a fuse in the air cond and the heater slot .... worth a try __________________ 71 C10 LWB 350sbc -TH350 12 bolt 3.42 Posi Of all my favorite things to do, The utmost is to have a brew. My love grows for my foamy friend, with each thirst-quenching elbow bend. Beer so frosty, smooth, and cold it's paradise pure liquid gold. Yes beer means many things to me that's all for now cus I gotta pee.

11-13-2003, 10:57 PM	#9
jimfulco Registered User Join Date: May 2003 Location: Shreveport LA Posts: 3,170	The connector lugs on the blower relay (the little silver box) and on the resistor on my Sub are prone to corrosion, so every year I have to clean them (or at least wiggle them) before the heat will blow. The contacts inside the relay also are a bit finicky, & when they don't conduct, nothing blows. Sometimes a good thump on the cover will fix it for a while.

11-13-2003, 11:34 PM	#10
1985K10 Registered User Join Date: Oct 2003 Location: CT Posts: 315	My dads 98 Silverado lost everything but High. He changed the resistor block and it was cured...for a month or so, now only high works again. If you have nothing at all id try bypassing the switch to see if its bad. __________________ Anthony 07 Tahoe LT 70 Chevelle 450HP 383-TH400 77 GMC Royal Sierra~Resto in progress~

11-14-2003, 10:26 PM	#11
mike reeh 5 day ban, learn to behave. Join Date: Nov 2002 Location: san diego, ca Posts: 683	i would have to disagree, its almost never the interior switch :/ in my experiences anyways.. but yeah its probably the relay thats giving you problems.. jimfulco hit the nail on the head when he said they are finicky and prone to corrosion.. The resistor tends to rust and then disintegrate also, so I would replace them both.. they're not expensive. If you still cant get it working, let us know and we'll get it straightened out, the circuit is really quite simple mike

11-15-2003, 02:50 AM	#12
crackajacka Stylin Join Date: Sep 2001 Location: Tuttle, OK Posts: 620	ok whats do i need to ask for at the parts store when i go to get another resistor. __________________ Ive been traveling for some time, with my fishin pole and my bottle of shyne. Most Girls like finished products and just dont understand what a good addiction does for you http://www.paulwall.us/

11-15-2003, 06:09 AM	#13
mike reeh 5 day ban, learn to behave. Join Date: Nov 2002 Location: san diego, ca Posts: 683	blower motor resistor and blower motor relay mike

11-15-2003, 01:24 PM	#15
crossy Oh,you can't buy that new Join Date: Apr 2000 Location: Pennsville,N.J. 08070, USA Posts: 2,039	Ken's right , even with the carb number in hand i was not able to come home with the right choke parts for my 85 the first time. They have superceeded many part numbers into one more 'generic' number for old vehicles such as ours.. DAVE __________________ "been there, done that, ruined the T-shirt". 2007 LBZ GMC Sierra, ECSB 2006 LM7 RCSB Silverado 98 Vortec project. 94,3500,6.5L 4L80 81 SWB GMC POS finally gone 73 Pinto, stock, w/CragarSS's-eww LOTS of Cummins trucks.

11-16-2003, 01:03 AM	#16
jimfulco Registered User Join Date: May 2003 Location: Shreveport LA Posts: 3,170	It just occurred to me that sometimes the function switch (heat, defrost, etc.) on mine has to be in exactly the right place for the fan to blow. Give everything a wiggle before you drop a bunch of cash.



Register or Log In To remove these advertisements.

11-16-2003, 01:30 AM	#17
crackajacka Stylin Join Date: Sep 2001 Location: Tuttle, OK Posts: 620	well its the resistor thing, i can pull the plug then jump the connections with a piece of wire and select high,med,low,lowlow and connect 2 ports and it blows on that setting __________________ Ive been traveling for some time, with my fishin pole and my bottle of shyne. Most Girls like finished products and just dont understand what a good addiction does for you http://www.paulwall.us/

11-16-2003, 09:26 PM	#18
crackajacka Stylin Join Date: Sep 2001 Location: Tuttle, OK Posts: 620	still not blowing grrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr, replaced the resistor and still nothing? what do i need to check next? n how __________________ Ive been traveling for some time, with my fishin pole and my bottle of shyne. Most Girls like finished products and just dont understand what a good addiction does for you http://www.paulwall.us/

11-18-2003, 02:12 AM	#19
apstguy LED King Join Date: Jan 2003 Location: Sacramento, CA Posts: 2,087	The blower switch. Have you used a multi-meter and checked all the wires? __________________ Tyler 1985 C10 305 w/ Bowtie OD TH700R4 3.42 LSD 202,000 miles 2006 Ford Focus ZX3 5-speed Stick 2016 Chevy Spark EV Gone: 2002.5 VW GTI 24v VR6 Gone: 2008 VW R32

11-19-2003, 05:14 PM	#20
suburbasaurus Registered User Join Date: Nov 2003 Location: Bee Bayou, La Posts: 9	i dont know if i understand the problem here but the switch in the dash sends power to the high speed relay "little silver box on side of the a/c box" if you have power there the dash switch is good. the high speed relay is the problem if you jumped the curcits and it blows. you can get one at any parts store for $15 or less. we sell them at O'Reilly's for under $15.00. the problem with my burb was it wouldnt work on high. pulled one off another truck and it works fine now. good luck and hope this helps!

Thread Tools
Show Printable Version Email this Page
Display Modes
Switch to Linear Mode Hybrid Mode Switch to Threaded Mode

Register or Log In To remove these advertisements.