1977 corvette max air doesnt work
Thread Starter
1st Gear
Joined: Jun 2014
Posts: 1
Likes: 0
From: colonial heights va
1977 corvette max air doesnt work
Hello,
I have replaced everything I know including blower motor,resister, etc... my medium air blows cold but about half the volume. Max air nothing comes out HELP
I have replaced everything I know including blower motor,resister, etc... my medium air blows cold but about half the volume. Max air nothing comes out HELP
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
You can have a lack of vacuum as mentioned going to the control head...ad you also can have a broken part in the heater box that is not allowing the door to move correctly...which is NOT uncommon....and can effect air flow.
The hot/cold lever does NOT control this door inside your heater box that I am writing about. it is vacuum operated.
Also...it is not uncommon that the leading face of your evaporator core is covered with debris which will effect the air flow.
DUB
Le Mans Master
Joined: Dec 2007
Posts: 6,422
Likes: 591
From: McHenry Illinois
Ok, I gotta correct myself a bit. Behind the left dash is a vacuum switch(just did this today) that when the temperature control is all the way to cold, will activate and send vacuum to the hot water shut off valve in the heater hose under the hood.
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,852
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
In most cases, issues with Hi Blow are generated from either a faulty relay or the wire connector on the relay is melted. The exhaust heat has been known to melt the connector that plugs into this relay.
Hi Blow is controlled by the orange wire.. so it's pretty easy to check if you know how.
Willcox.
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
NOT behind the LEFT DASH...because the 'left dash' is the dash panel that has your speedometer and tachometer in it....and the vacuum switch for the hot water shut off valve is behind the RIGHT dash panel and this vacuum switch is located on top of the heater box....and that has NOTHING to do with what his problem is. His problem has to be electrical. OR...it is like what I wrote where the plastic retainer is broken and it can not sweep correctly...because it is vacuum controlled....and will not allow the air to be routed correctly.
DUB
Le Mans Master
Joined: Sep 2003
Posts: 8,812
Likes: 2,029
From: eastern NC
IF this is the case, you can access the valve body by removing the passenger side panel on the console.
Good luck... GUSTO
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Le Mans Master
Joined: Dec 2007
Posts: 6,422
Likes: 591
From: McHenry Illinois
Correction:
NOT behind the LEFT DASH...because the 'left dash' is the dash panel that has your speedometer and tachometer in it....and the vacuum switch for the hot water shut off valve is behind the RIGHT dash panel and this vacuum switch is located on top of the heater box....and that has NOTHING to do with what his problem is. His problem has to be electrical. OR...it is like what I wrote where the plastic retainer is broken and it can not sweep correctly...because it is vacuum controlled....and will not allow the air to be routed correctly.
DUB
NOT behind the LEFT DASH...because the 'left dash' is the dash panel that has your speedometer and tachometer in it....and the vacuum switch for the hot water shut off valve is behind the RIGHT dash panel and this vacuum switch is located on top of the heater box....and that has NOTHING to do with what his problem is. His problem has to be electrical. OR...it is like what I wrote where the plastic retainer is broken and it can not sweep correctly...because it is vacuum controlled....and will not allow the air to be routed correctly.
DUB