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#1 |
Registered User
Join Date: Jun 2013
Location: Marilla, NY
Posts: 112
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heat/cooling issues
My 78 blows air temperature air no matter what the temperature switch is set at. Blows hot air in the summer, and cold air in the winter, no matter what. What could possibly be wrong with it and what would it take to fix it so it functions properly? Since Im going to be driving my truck all summer, I dont want it to blow hot air when its not even set on hot. Also, I do not have air conditioning if that helps.
Lastly, in a previous thread, I heard that the only way the fan can be shut all the way off is by cutting one of the wires to the fan speed switch, which wire is the one that goes to the lowest power on a 3 speed switch?
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-1978 ![]() 400 SBC 4 spd muncie SM465 ("heavy chevy") -2002 Toyota Celica GT 5spd (gas saving daily driver) -1969 Pontiac Firebird (post-college project car) |
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#2 |
Registered User
Join Date: Feb 2008
Location: Tacoma Washington
Posts: 890
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Re: heat/cooling issues
Is the valve to your heater core moving when you adjust the temp? The only other things coming to mind are low coolant or a bypassed core.
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I know a guy who's addicted to brake fluid. He says he can stop any time. 72 K10 396 75 Cj5 MPI 350 Chev 67 Chevelle 396, 4 speed 74 FXE 08 Tahoe |
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#3 |
Account Suspended
Join Date: Jun 2011
Location: Des Moines, IA.
Posts: 4,143
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Re: heat/cooling issues
Also, check the main blend door threaded rod holder-if it breaks, the door it always open which prevents the air from moving through the various vent settings. And yes, the low speed is always on with key on....you have to cut and cap that lead.
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#4 |
Registered User
Join Date: Jun 2013
Location: Marilla, NY
Posts: 112
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Re: heat/cooling issues
When I adjust the temp, I hear a "thump" sound coming from inside the dash, so im guessing it is doing something. Last I checked, the radiator is topped off on coolant, and no clue if the core has been bypassed or not.
__________________
-1978 ![]() 400 SBC 4 spd muncie SM465 ("heavy chevy") -2002 Toyota Celica GT 5spd (gas saving daily driver) -1969 Pontiac Firebird (post-college project car) |
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