Ventilation Question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Agteacher · 10-11-2005, 04:52 PM

I have an '87 Chevy 1/2 ton 4x4. I can't get it to switch from heater, to defroster, to vent, etc. The temperature control works fine. I took it apart and found the door which directs the airflow, but i am not sure what actuates it. There is a vacuum line that goes to the right kick panel. The line has a tee, and this line is not attached to anything. It is obviously broken, but I am not sure from where. It appeared to go up toward the passenger speaker in the dash. Is this vacuum line my problem, and if so where does it attach?

86 GMG · 10-11-2005, 05:08 PM

it is more than likely the problem you can remove the glove box and gain access to more area of the heater \a/c unit under the dash which may alloy you to see where it goes. does the switch on the heater unit in the dash move freely or does it seam bound up? there maybe a hole through the fire wall that the vacuum line you speak of may go through to connect to a vacuum point under the hood. i really cant give you a straight forward answer to where it goes but i can give you some help to maybe find the location best regards 86 gmg

koreric75 · 10-11-2005, 06:16 PM

i think there is a diaphram under the hood cowl and black plastic screen material on the passender side, i just noticed it this past weekend when i removed the stuff to clean out the area since there were tons of pine needles in there.

Agteacher · 10-12-2005, 04:41 PM

Thanks for the help. The door moves, but it feels as if it is spring loaded to return to center. I will try to look today to see what lies under the cowl.

86 GMG · 10-12-2005, 04:57 PM

Thanks for the help. The door moves, but it feels as if it is spring loaded to return to center. I will try to look today to see what lies under the cowl.
Reply With Quotethere is a sertin amount that you can adjust on the top side of the black box behind the glovebox i personally didnt adjust mine but my friend did and it works good know hope this helps (agteacher) doesnt your ag class have a ag mechanics like what was available for me in h.s. if so talk to someone in there to assist you in this if needed.

10-11-2005, 04:52 PM	#1
Agteacher Registered User Join Date: Oct 2005 Location: Amarillo Posts: 2	Ventilation Question I have an '87 Chevy 1/2 ton 4x4. I can't get it to switch from heater, to defroster, to vent, etc. The temperature control works fine. I took it apart and found the door which directs the airflow, but i am not sure what actuates it. There is a vacuum line that goes to the right kick panel. The line has a tee, and this line is not attached to anything. It is obviously broken, but I am not sure from where. It appeared to go up toward the passenger speaker in the dash. Is this vacuum line my problem, and if so where does it attach?

10-11-2005, 05:08 PM	#2
86 GMG Registered User Join Date: Apr 2005 Location: Tulsa Oklahoma Posts: 943	it is more than likely the problem you can remove the glove box and gain access to more area of the heater \a/c unit under the dash which may alloy you to see where it goes. does the switch on the heater unit in the dash move freely or does it seam bound up? there maybe a hole through the fire wall that the vacuum line you speak of may go through to connect to a vacuum point under the hood. i really cant give you a straight forward answer to where it goes but i can give you some help to maybe find the location best regards 86 gmg __________________ square body trucks an addiction or an investment either way they consume all my extra time and money

10-11-2005, 06:16 PM	#3
koreric75 83C10SWB Join Date: Sep 2005 Location: Bossier City, Louisiana Posts: 69	i think there is a diaphram under the hood cowl and black plastic screen material on the passender side, i just noticed it this past weekend when i removed the stuff to clean out the area since there were tons of pine needles in there. __________________ Koreric75 2003 Suburban Z-71 4x4 5.3L 83 C10 SWB FOR SALE 350ci/700Raptor Jr Picture&Progress Page

10-12-2005, 04:57 PM	#5
86 GMG Registered User Join Date: Apr 2005 Location: Tulsa Oklahoma Posts: 943	Thanks for the help. The door moves, but it feels as if it is spring loaded to return to center. I will try to look today to see what lies under the cowl. Reply With Quotethere is a sertin amount that you can adjust on the top side of the black box behind the glovebox i personally didnt adjust mine but my friend did and it works good know hope this helps (agteacher) doesnt your ag class have a ag mechanics like what was available for me in h.s. if so talk to someone in there to assist you in this if needed. __________________ square body trucks an addiction or an investment either way they consume all my extra time and money

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10-12-2005, 04:41 PM	#4
Agteacher Registered User Join Date: Oct 2005 Location: Amarillo Posts: 2	Thanks for the help. The door moves, but it feels as if it is spring loaded to return to center. I will try to look today to see what lies under the cowl.



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