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73-87 Chevy _ GMC Trucks => Interior & Equipment => Heating, Ventilation & Air Conditioning (HVAC) => Topic started by: philo_beddoe on January 29, 2020, 10:12:50 pm

Title: No med. or low on blower motor..
Post by: philo_beddoe on January 29, 2020, 10:12:50 pm: It appears the heat (fan) setting only cranks on high. I cant hear it go from low to med. Why is this?

Don't think its the blower motor...hi, med, low fan switch?

(https://uploads.tapatalk-cdn.com/20200130/878154dcd264c0f7a48c15502c985db7.jpg)
Title: Re: No med. or low on blower motor..
Post by: VileZambonie on January 30, 2020, 04:40:13 am: Check the blower motor resistor.
Title: Re: No med. or low on blower motor..
Post by: Sideways the Seven on January 30, 2020, 08:29:29 am: I just noticed I have this same issue, this morning. Where is the resistor located?
Title: Re: No med. or low on blower motor..
Post by: zieg85 on January 30, 2020, 10:28:18 am: Non-AC is inside the cab behind the glove box door I think. AC versions is outside on the AC box on top. When I suspect something I have no clue my first step is to go to Autozone site, figure out what I need then find a picture to know what I am looking for, for my particular application.
Title: Re: No med. or low on blower motor..
Post by: Rapid Roy on January 30, 2020, 11:24:18 am: FYI (pic)

I removed the top wire (yellow) from the connector on resistor so fan does not run on the low speed when key on. When I first start in the early mornings, when vacuum goes down, fan was always blowing from top vents and in winter I had cold air blowing in my face. Not sure what all models has this type. This was with the help of an electronics engineer co-worker. Now fan has an OFF position. It now seems more normal.
Title: No med. or low on blower motor..
Post by: philo_beddoe on February 03, 2020, 10:15:53 pm: Ok, i'll check that resistor, shouldnt be a problem. Been wrestling with a 1991 Husqvarna chain saw, nearly gave up the ghost, but i saved it. Rips and screams again.

(https://uploads.tapatalk-cdn.com/20200204/d1aaf294773b84969e853e4304aee214.jpg)
Title: Re: No med. or low on blower motor..
Post by: Sideways the Seven on February 19, 2020, 08:25:42 am: Quote from: zieg85 on January 30, 2020, 10:28:18 am
Non-AC is inside the cab behind the glove box door I think. AC versions is outside on the AC box on top. When I suspect something I have no clue my first step is to go to Autozone site, figure out what I need then find a picture to know what I am looking for, for my particular application.

Ah, thanks!
Title: Re: No med. or low on blower motor..
Post by: Sideways the Seven on February 20, 2020, 09:34:44 pm: Welp, the resistor didn't work for me. Guess I'll check the relay

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Title: Re: No med. or low on blower motor..
Post by: VileZambonie on February 21, 2020, 04:14:25 pm: Fire the parts cannon
Title: Re: No med. or low on blower motor..
Post by: Sideways the Seven on February 21, 2020, 06:24:56 pm: Quote from: VileZambonie on February 21, 2020, 04:14:25 pm
Fire the parts cannon
LMAO I'm not going quite that far. I think an extra one came with the truck along with an extra blower motor and whatnot.

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Title: No med. or low on blower motor..
Post by: philo_beddoe on February 23, 2020, 10:05:01 pm: Gotta love the parts cannon, end up with a buncha new stuff and it still doesn't work! lol...
Found one, $12, O'Reilly.

(https://uploads.tapatalk-cdn.com/20200224/ff6505c692f76b9ddc045859dea5cd33.jpg)
Title: Re: No med. or low on blower motor..
Post by: VileZambonie on February 24, 2020, 03:53:11 pm: Is your truck AC or non AC? The resistor is dfifferent.
Title: Re: No med. or low on blower motor..
Post by: JohnnyPopper on February 25, 2020, 08:23:57 am: Quote from: philo_beddoe on January 29, 2020, 10:12:50 pm
It appears the heat (fan) setting only cranks on high. I cant hear it go from low to med. Why is this?

Don't think its the blower motor...hi, med, low fan switch?

(https://uploads.tapatalk-cdn.com/20200130/878154dcd264c0f7a48c15502c985db7.jpg)

The problem is obvious: you're on the wrong radio station!
Title: Re: No med. or low on blower motor..
Post by: philo_beddoe on March 03, 2020, 05:59:32 pm: Quote from: JohnnyPopper on February 25, 2020, 08:23:57 am
Quote from: philo_beddoe on January 29, 2020, 10:12:50 pm
It appears the heat (fan) setting only cranks on high. I cant hear it go from low to med. Why is this?

Don't think its the blower motor...hi, med, low fan switch?

(https://uploads.tapatalk-cdn.com/20200130/878154dcd264c0f7a48c15502c985db7.jpg)

The problem is obvious: you're on the wrong radio station!
No way man! I listen too conservative talk radio only.

(https://uploads.tapatalk-cdn.com/20200303/74e63ef29ce7414b7da2303459a48657.jpg)
Title: Re: No med. or low on blower motor..
Post by: philo_beddoe on March 03, 2020, 06:00:21 pm: Quote from: VileZambonie on February 24, 2020, 03:53:11 pm
Is your truck AC or non AC? The resistor is dfifferent.
Non A/C, the pic is for non i believe.
Title: Re: No med. or low on blower motor..
Post by: Sideways the Seven on March 05, 2020, 02:30:15 pm: Quote from: VileZambonie on February 21, 2020, 04:14:25 pm
Fire the parts cannon
Ok, so there were plenty of relays in my bags of spare parts but nothing for the blower motor. So I DON'T have to fire the parts cannon, what else could it be if it's not the resistor?

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Title: Re: No med. or low on blower motor..
Post by: VileZambonie on March 05, 2020, 03:10:18 pm: Quote from: Sideways the Seven on March 05, 2020, 02:30:15 pm
Quote from: VileZambonie on February 21, 2020, 04:14:25 pm
Fire the parts cannon
Ok, so there were plenty of relays in my bags of spare parts but nothing for the blower motor. So I DON'T have to fire the parts cannon, what else could it be if it's not the resistor?

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What are you working on? Does it have AC? What's your problem, high speed only?
Title: Re: No med. or low on blower motor..
Post by: Sideways the Seven on March 05, 2020, 06:46:45 pm: Quote from: VileZambonie on March 05, 2020, 03:10:18 pm
Quote from: Sideways the Seven on March 05, 2020, 02:30:15 pm
Quote from: VileZambonie on February 21, 2020, 04:14:25 pm
Fire the parts cannon
Ok, so there were plenty of relays in my bags of spare parts but nothing for the blower motor. So I DON'T have to fire the parts cannon, what else could it be if it's not the resistor?

Sent from my GM1915 using Tapatalk

What are you working on? Does it have AC? What's your problem, high speed only?
It's an '87 Burb with A/C. The fan only blows on high. I already swapped the resistor

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Title: No med. or low on blower motor..
Post by: philo_beddoe on March 05, 2020, 09:54:54 pm: Same problem here, and i aint tried nothin,,and im all out of ideas!! Doh!!!
Title: Re: No med. or low on blower motor..
Post by: VileZambonie on March 06, 2020, 06:36:03 pm: 1)With AC

2)Without AC
Title: Re: No med. or low on blower motor..
Post by: Sideways the Seven on March 06, 2020, 06:55:57 pm: Quote from: VileZambonie on March 06, 2020, 06:36:03 pm
1)With AC

2)Without AC
Thanks!!

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Title: Re: No med. or low on blower motor..
Post by: philo_beddoe on April 14, 2020, 07:43:36 pm: Oh, BTW, VZ was right. I finally stopped into an O'riellys and got a new resistor for the heater. Installed and now all three levels work, low-med-high.

(https://uploads.tapatalk-cdn.com/20200415/34d4d9e275cbae2866a710e1d6d72618.jpg)
(https://uploads.tapatalk-cdn.com/20200415/878eb80ef6b34ce8600550c5bb8dd712.jpg)
(https://uploads.tapatalk-cdn.com/20200415/4c3ad8cb1f22f6976c0eb83f6285d528.jpg)
Title: No med. or low on blower motor..
Post by: philo_beddoe on May 26, 2020, 10:04:51 pm: Not so fast, it still doesn’t work on med. But it does run on the low setting as soon as I turn the key...as it should. I could swear it worked on all three settings after replacing the resistor. Think it could be low-med-high switch? Won’t need until Oct. anyway.

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Title: Re: No med. or low on blower motor..
Post by: VileZambonie on May 27, 2020, 05:53:07 am: Put it on medium with the key on and go mess with the connection at the resistor. If it starts working then you have corroded connections.
Title: Re: No med. or low on blower motor..
Post by: philo_beddoe on June 21, 2020, 06:34:59 am: Knowing me its probably clean, i despise corrosion. But will go try that anyway and let you know. Thanks
Title: Re: No med. or low on blower motor..
Post by: philo_beddoe on November 27, 2020, 07:53:25 am: Quote from: VileZambonie on May 27, 2020, 05:53:07 am
Put it on medium with the key on and go mess with the connection at the resistor. If it starts working then you have corroded connections.
Update: yes it was corroded connections, disassembled, cleaned and re-attached. Lo-med-hi work great.