Electrical question for ya'll. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

krue · 11-01-2004, 08:08 PM

My blower motor has been blowing 30a fuses off and on. The motor will run for a while then the fuse will blow. With the ignition off I disconnected the purple wire from my a/c blower motor. I tested for ground on the spade on the motor and got a reading of .5ohms, the same reading I got when touching the probes together. I tested back through the switch (in HI position) and got a reading of 12.5ohms. What would be normal readings? Is the switch or blower or both bad?

JimKshortstep4x4 · 11-01-2004, 09:23 PM

I just checked a couple of blower motors and got .6 and .7 ohms which is very close to your reading on your motor. It sounds like you are loosing contact slightly in your switch but that would not cause blowing of the fuses.

I suspect that you have a blower motor problem and you should be able to check the draw when it is running if you have the right ammeter setup. ( I use an ammeter that read by placing it over the wire).

Jim

68w/sbc406 · 11-01-2004, 09:40 PM

put a 35 in and call it good

68LSS1 · 11-02-2004, 02:12 AM

Yes, it sounds like your blower motor is tired and pulling too much amperage blowing the fuse. Usually, not always, but usually, a short to ground will blow the fuse instantaneously.

**1970 CST Short Wide** · 11-02-2004, 11:04 AM

There is a ? rheostat ? Up under the heater box. Mine was doing the same thing. I found the ? rheostat? thing and replaced it. Heater works like a charm.

Sorry I donâ€™t know exactly what you call it. Its hidden up on the heater box though, just follow the wires you'll find it

Longhorn Man · 11-02-2004, 08:13 PM

That is a resistor in the heater box...normally they either work, or don't work. (Although, there is the chance that it is at fault)
IMO, I think the motor is getting old and tired. Does it make any squeeling or rumbling noises? Drill a real small hole dead center on the sheet metal of the blower motor. You don't even need to remove it from the truck. There is a raised nipple, drill it in the center, and then put some graphite powder...or spray in the hole. Use a small dab of silicone to re-seal the hole. Do not operate untill sillicone is dry.
If this solves the problem, then your motor is on borrowed time. however, i have seen blower motors fo 5 more years after doing this. Personally, mine is about to hit 4 years on this repair...and still blowing hard too.

krue · 11-02-2004, 09:08 PM

$13 dollars at O'reilly's for a new blower motor, now I just gotta find the time to install it. Thanks for the help guys!

Longhorn Man · 11-02-2004, 10:42 PM

mannn, last time i checked into a new blower, I was quoted 45 bucks....which is why mine has silicone on the end of it.
Still, it is a quickie that does work.

68w/sbc406 · 11-02-2004, 10:44 PM

Quote:

Originally Posted by Longhorn Man

it is a quickie that does work.

you like those quickies..................................fixes that is

Longhorn Man · 11-02-2004, 10:49 PM

I like them quick AND cheap.

68C15 · 11-02-2004, 11:47 PM

but do you like them clean or greasy & bloody? repairs that is.

Longhorn Man · 11-03-2004, 12:25 AM

lol

11-01-2004, 08:08 PM	#1
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,450	Electrical question for ya'll. My blower motor has been blowing 30a fuses off and on. The motor will run for a while then the fuse will blow. With the ignition off I disconnected the purple wire from my a/c blower motor. I tested for ground on the spade on the motor and got a reading of .5ohms, the same reading I got when touching the probes together. I tested back through the switch (in HI position) and got a reading of 12.5ohms. What would be normal readings? Is the switch or blower or both bad? __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

11-01-2004, 09:40 PM	#3
68w/sbc406 Got Light Emitting Diode? Join Date: Apr 2004 Location: Newberg, OR Posts: 2,485	put a 35 in and call it good __________________ 1968 1/2 ton 2wd lwb 6 lug disc and bags up front. Next c notch and rear bags '02 Chevy Silverado LT ext cab short bed 2WD 5/7 drop on 22's(the family car) 1993 Cherokee work ride/weekend wheeler

11-02-2004, 02:12 AM	#4
68LSS1 Registered User Join Date: Dec 2002 Location: Tampa Posts: 1,191	Yes, it sounds like your blower motor is tired and pulling too much amperage blowing the fuse. Usually, not always, but usually, a short to ground will blow the fuse instantaneously. __________________ '68 Short Step LS1/T56, Hydratech, Fatman Fabrications Stage III, Baer, Hot Rods to Hell, US Body, S&W, etc

11-02-2004, 11:04 AM	#5
1970 CST Short Wide Senior Moment Join Date: Mar 2002 Location: Pittsburg Ca Posts: 4,165	There is a ? rheostat ? Up under the heater box. Mine was doing the same thing. I found the ? rheostat? thing and replaced it. Heater works like a charm. Sorry I donâ€™t know exactly what you call it. Its hidden up on the heater box though, just follow the wires you'll find it __________________ 1970 CST LS 1 6 speed Ford 9 inch Detroit Tru Track, Dakota Didgital, Vintage Air, QA1 Coil Overs Front & Rear Lots of FUN 2013 GMC PU, Oldest Son 71 GMC LWB. QA1 Suspension, Angry SB. Youngest Son 2019 GMC Diesil Dually. Youngest Son 2017 Toyota SUV Daughters car 2018 Traverse , Wife’s Ride Pittsburg Ca 94565

11-02-2004, 09:08 PM	#7
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,450	$13 dollars at O'reilly's for a new blower motor, now I just gotta find the time to install it. Thanks for the help guys! __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

11-01-2004, 09:23 PM	#2
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	I just checked a couple of blower motors and got .6 and .7 ohms which is very close to your reading on your motor. It sounds like you are loosing contact slightly in your switch but that would not cause blowing of the fuses. I suspect that you have a blower motor problem and you should be able to check the draw when it is running if you have the right ammeter setup. ( I use an ammeter that read by placing it over the wire). Jim

11-02-2004, 08:13 PM	#6
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	That is a resistor in the heater box...normally they either work, or don't work. (Although, there is the chance that it is at fault) IMO, I think the motor is getting old and tired. Does it make any squeeling or rumbling noises? Drill a real small hole dead center on the sheet metal of the blower motor. You don't even need to remove it from the truck. There is a raised nipple, drill it in the center, and then put some graphite powder...or spray in the hole. Use a small dab of silicone to re-seal the hole. Do not operate untill sillicone is dry. If this solves the problem, then your motor is on borrowed time. however, i have seen blower motors fo 5 more years after doing this. Personally, mine is about to hit 4 years on this repair...and still blowing hard too.

11-02-2004, 10:42 PM	#8
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	mannn, last time i checked into a new blower, I was quoted 45 bucks....which is why mine has silicone on the end of it. Still, it is a quickie that does work.

11-02-2004, 10:49 PM	#10
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	I like them quick AND cheap.

11-02-2004, 11:47 PM	#11
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	but do you like them clean or greasy & bloody? repairs that is. __________________ Man rule #77...if you own a 67 stepside with a caddy 472 you will never be in danger of loosing you man card

11-03-2004, 12:25 AM	#12
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	lol

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