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HVAC FAN Problem... [message #82971] Mon, 03 May 2010 21:45 Go to next message
amdgmcman is currently offline  amdgmcman   United States
Messages: 76
Registered: April 2007
Location: Long Beach, CA
Karma: 0
Member
Greetings,

My dash heater-A/C fan has quit working. I hear a sound that I swear resembles a “frozen” fan from under the dash near the glove box when I move the dash panel lever to either A/C or vent that goes away after a minute of so. I removed the fan, (or I think it is - inside the front passenger side hood), and it spins freely. What am I missing here?

I’m back … and I bought my dad’s ’78 Royale from the estate … its all mine …(and my new bride’s)

- Alan DeLuccio
AMDGMCMan
Long Beach, CA
'78 Royale w/ Coachman center kitchen floor plan


AMDGMCMan
Alan M DeLuccio
78 Royale with
Coachmen,Center Kitchen Floorplan
09 Harley Davidson Street Glide
65 Corvair Monza Convertible
96 RAV4 2 door Manual 4WD
Long Beach, CA
Re: [GMCnet] HVAC FAN Problem... [message #82973 is a reply to message #82971] Mon, 03 May 2010 22:17 Go to previous messageGo to next message
ljdavick is currently offline  ljdavick   United States
Messages: 3548
Registered: March 2007
Location: Fremont, CA
Karma: -3
Senior Member
Alan,

Congradulations! You are a lucky one to have a '78, they have the best dash air. Have you looked at Gene's <www.gmcmotorhome.info> site? I was looking at this just today <http://gmcmotorhome.info/list.html#heat>. I also read this excellent overview <http://www.gmcws.org/Tech/air_conditioning/air_conditing.html>.

Welcome to the asylum!

Larry Davick
The Mystery Machine
Sent from my iPad

On May 3, 2010, at 7:45 PM, Alan M DeLuccio <delbassman@yahoo.com> wrote:

>
>
> Greetings,
>
> My dash heater-A/C fan has quit working. I hear a sound that I swear resembles a &#8220;frozen&#8221; fan from under the dash near the glove box when I move the dash panel lever to either A/C or vent that goes away after a minute of so. I removed the fan, (or I think it is - inside the front passenger side hood), and it spins freely. What am I missing here?
>
> I&#8217;m back &#8230; and I bought my dad&#8217;s &#8217;78 Royale from the estate &#8230; its all mine &#8230;(and my new bride&#8217;s)
>
> - Alan DeLuccio
> AMDGMCMan
> Long Beach, CA
> '78 Royale w/ Coachman center kitchen floor plan
>
> --
> AMDGMCMan
> Alan M DeLuccio
> 78 Royale with
> Coachman Center Kitchen Floorplan
> Redondo Beach, CA
>
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
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Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, Ca
Howell EFI + EBL + Electronic Dizzy
Re: [GMCnet] HVAC FAN Problem... [message #83009 is a reply to message #82971] Tue, 04 May 2010 10:10 Go to previous messageGo to next message
Mr ERFisher is currently offline  Mr ERFisher   United States
Messages: 7117
Registered: August 2005
Karma: 2
Senior Member
here is some stuff to read

http://gmcmotorhome.info/heat.html#fan

gene



On Mon, May 3, 2010 at 7:45 PM, Alan M DeLuccio <delbassman@yahoo.com>wrote:

>
>
> Greetings,
>
> My dash heater-A/C fan has quit working. I hear a sound that I swear
> resembles a “frozen” fan from under the dash near the glove box when I move
> the dash panel lever to either A/C or vent that goes away after a minute of
> so. I removed the fan, (or I think it is - inside the front passenger side
> hood), and it spins freely. What am I missing here?
>
> I’m back … and I bought my dad’s ’78 Royale from the estate … its all mine
> …(and my new bride’s)
>
> - Alan DeLuccio
> AMDGMCMan
> Long Beach, CA
> '78 Royale w/ Coachman center kitchen floor plan
>
> --
> AMDGMCMan
> Alan M DeLuccio
> 78 Royale with
> Coachman Center Kitchen Floorplan
> Redondo Beach, CA
>
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>



--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
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Re: HVAC FAN Problem... [message #83086 is a reply to message #82971] Tue, 04 May 2010 21:16 Go to previous messageGo to next message
amdgmcman is currently offline  amdgmcman   United States
Messages: 76
Registered: April 2007
Location: Long Beach, CA
Karma: 0
Member
Greetings,
Ok … When I switch on the HVAC control I hear the click of the relay, and when I pull the HTR – A/C fuse the click goes away, but when after I reinstall the fuse and check the power supply connection wire feeding the blower motor I only get a 0.05 volt reading. I followed wire from the connector into the firewall at where I believe it enters the fuse box under the inside of the dashboard and get a slightly higher reading. I’m lost!


AMDGMCMan
Alan M DeLuccio
78 Royale with
Coachmen,Center Kitchen Floorplan
09 Harley Davidson Street Glide
65 Corvair Monza Convertible
96 RAV4 2 door Manual 4WD
Long Beach, CA
Re: [GMCnet] HVAC FAN Problem... [message #83100 is a reply to message #83086] Tue, 04 May 2010 22:44 Go to previous messageGo to next message
GMCWiperMan is currently offline  GMCWiperMan   United States
Messages: 1248
Registered: December 2007
Karma: 1
Senior Member
Alan,

Are you following the wiring diagram as you attempt to trace the circuit?
If not, you need to stop wasting your time and get one. If you do have the
wiring diagram, you can see that the power to the motor must pass through
the relay contacts, so that's a prime suspect.

You can also see that if you're selecting the HI blower position with the
engine not running, there will be no voltage to the motor. Since you report
hearing the relay click when turning the switch on, I suspect this is the
reason for your low voltage reading -- there's no voltage to read if the
relay closes with no alternator output.

Ken H.

On Tue, May 4, 2010 at 10:16 PM, Alan M DeLuccio <delbassman@yahoo.com>wrote:

>
>
> Greetings,
> Ok … When I switch on the HVAC control I hear the click of the relay, and
> when I pull the HTR – A/C fuse the click goes away, but when after I
> reinstall the fuse and check the power supply connection wire feeding the
> blower motor I only get a 0.05 volt reading. I followed wire from the
> connector into the firewall at where I believe it enters the fuse box under
> the inside of the dashboard and get a slightly higher reading. I’m lost!
> --
> AMDGMCMan
> Alan M DeLuccio
> 78 Royale with
> Coachmen,Center Kitchen Floorplan
> Long Beach, CA
>
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

Re: [GMCnet] HVAC FAN Problem... [message #83125 is a reply to message #83100] Wed, 05 May 2010 07:40 Go to previous messageGo to next message
Steven Ferguson is currently offline  Steven Ferguson   United States
Messages: 3447
Registered: May 2006
Karma: 0
Senior Member
Isn't the "click" the compressor clutch engaging?

On Tue, May 4, 2010 at 8:44 PM, Ken Henderson <ken0henderson@gmail.com> wrote:
> Alan,
>
> Are you following the wiring diagram as you attempt to trace the circuit?
>  If not, you need to stop wasting your time and get one.  If you do have the
> wiring diagram, you can see that the power to the motor must pass through
> the relay contacts, so that's a prime suspect.
>
> You can also see that if you're selecting the HI blower position with the
> engine not running, there will be no voltage to the motor.  Since you report
> hearing the relay click when turning the switch on, I suspect this is the
> reason for your low voltage reading -- there's no voltage to read if the
> relay closes with no alternator output.
>
> Ken H.
>
> On Tue, May 4, 2010 at 10:16 PM, Alan M DeLuccio <delbassman@yahoo.com>wrote:
>
>>
>>
>> Greetings,
>> Ok … When I switch on the HVAC control I hear the click of the relay, and
>> when I pull the HTR – A/C fuse the click goes away, but when after I
>> reinstall the fuse and check the power supply connection wire feeding the
>> blower motor I only get a 0.05 volt reading. I followed wire from the
>> connector into the firewall at where I believe it enters the fuse box under
>> the inside of the dashboard and get a slightly higher reading. I’m lost!
>> --
>> AMDGMCMan
>> Alan M DeLuccio
>> 78 Royale with
>> Coachmen,Center Kitchen Floorplan
>> Long Beach, CA
>>
>> _______________________________________________
>> GMCnet mailing list
>> List Information and Subscription Options:
>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>>
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>



--
Steve Ferguson
'76 EII
Sierra Vista, AZ
Urethane bushing source
www.bdub.net/ferguson/
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Re: HVAC FAN Problem... [message #83128 is a reply to message #82971] Wed, 05 May 2010 07:55 Go to previous messageGo to next message
C Boyd is currently offline  C Boyd   United States
Messages: 2629
Registered: April 2006
Karma: 18
Senior Member
amdgmcman wrote on Mon, 03 May 2010 22:45

Greetings,

My dash heater-A/C fan has quit working. I hear a sound that I swear resembles a “frozen” fan from under the dash near the glove box when I move the dash panel lever to either A/C or vent that goes away after a minute of so. I removed the fan, (or I think it is - inside the front passenger side hood), and it spins freely. What am I missing here?

I’m back … and I bought my dad’s ’78 Royale from the estate … its all mine …(and my new bride’s)

- Alan DeLuccio
AMDGMCMan
Long Beach, CA
'78 Royale w/ Coachman center kitchen floor plan








Sir: maybe a loose ground wire to the fan motor? I had this issue leaving Bean Station.


C. Boyd
76 Crestmont
East Tennessee
Re: [GMCnet] HVAC FAN Problem... [message #83174 is a reply to message #83125] Wed, 05 May 2010 12:13 Go to previous message
GMCWiperMan is currently offline  GMCWiperMan   United States
Messages: 1248
Registered: December 2007
Karma: 1
Senior Member
Well, yeah, it could be, but he said near the glove box -- I figured his
hearing is better than mine. :-)

Chuck's idea about a loose ground also identified a very common problem --
but the low voltage reading would only occur if he's using the fan housing
as the reference for the voltmeter.

We really need more detailed information about the troubleshooting procedure
in use.

Ken H.


On Wed, May 5, 2010 at 8:40 AM, Steven Ferguson <botiemad11@gmail.com>wrote:

> Isn't the "click" the compressor clutch engaging?
>
> On Tue, May 4, 2010 at 8:44 PM, Ken Henderson <ken0henderson@gmail.com>
> wrote:
> > Alan,
> >
> > Are you following the wiring diagram as you attempt to trace the circuit?
> > If not, you need to stop wasting your time and get one. If you do have
> the
> > wiring diagram, you can see that the power to the motor must pass through
> > the relay contacts, so that's a prime suspect.
> >
> > You can also see that if you're selecting the HI blower position with the
> > engine not running, there will be no voltage to the motor. Since you
> report
> > hearing the relay click when turning the switch on, I suspect this is the
> > reason for your low voltage reading -- there's no voltage to read if the
> > relay closes with no alternator output.
> >
> > Ken H.
> >
> > On Tue, May 4, 2010 at 10:16 PM, Alan M DeLuccio <delbassman@yahoo.com
> >wrote:
> >
> >>
> >>
> >> Greetings,
> >> Ok … When I switch on the HVAC control I hear the click of the relay,
> and
> >> when I pull the HTR – A/C fuse the click goes away, but when after I
> >> reinstall the fuse and check the power supply connection wire feeding
> the
> >> blower motor I only get a 0.05 volt reading. I followed wire from the
> >> connector into the firewall at where I believe it enters the fuse box
> under
> >> the inside of the dashboard and get a slightly higher reading. I’m lost!
> >> --
> >> AMDGMCMan
> >> Alan M DeLuccio
> >> 78 Royale with
> >> Coachmen,Center Kitchen Floorplan
> >> Long Beach, CA
> >>
> >> _______________________________________________
> >> GMCnet mailing list
> >> List Information and Subscription Options:
> >> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> >>
> > _______________________________________________
> > GMCnet mailing list
> > List Information and Subscription Options:
> > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> >
>
>
>
> --
> Steve Ferguson
> '76 EII
> Sierra Vista, AZ
> Urethane bushing source
> www.bdub.net/ferguson/
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
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