What is this on the firewall
Thread Starter
Intermediate
Joined: Jan 2010
Posts: 34
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From: nj
What is this on the firewall
I am new to the forum and love it. I have found answers to many questions already but this one I can't figure out. I have a 79 and on the firewall behind the driver side valve cover is some kind of valve. It looks like it gets a vacuum hose and has two terminals for wires. Anyone know what it is and where does the wires and hose come from. Help would be greatly appreciated. Thanks
Instructor
Joined: Jul 2007
Posts: 245
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From: Hope Indiana
I am new to the forum and love it. I have found answers to many questions already but this one I can't figure out. I have a 79 and on the firewall behind the driver side valve cover is some kind of valve. It looks like it gets a vacuum hose and has two terminals for wires. Anyone know what it is and where does the wires and hose come from. Help would be greatly appreciated. Thanks
Can't really tell you unless you post a picture I guess... Sorry!
Thread Starter
Intermediate
Joined: Jan 2010
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From: nj
There are two pictures in my album I hope this helps.
http://forums.corvetteforum.com/pict...ictureid=44202
http://forums.corvetteforum.com/pict...ictureid=44202
Drifting
Joined: Apr 2008
Posts: 1,565
Likes: 2
From: Sparta Mo.
Wow, that doesn't happen much on stuff like this. I've never seen a part similar to that on anything. I have absolutely NO idea what that is. It looks like a vacuum operated electrical switch. That is, when a certain vacuum is reached, it turns the switch on/off. Now I HAVE to find out so I know for the next time.
Race Director
Joined: May 2006
Posts: 16,528
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From: Dayton, Ohio
I've seen a very similar switch used to shut the AC compressor off during heavy acceleration but it is usually over next to the compressor.
I've also seen the switch used to open and close the headlights instead of using the vac switch on the headlights.
Years ago 1 of the vendors sold a kit with a vac switch that made 1 of the headlights "wink".
I've also seen the switch used to open and close the headlights instead of using the vac switch on the headlights.
Years ago 1 of the vendors sold a kit with a vac switch that made 1 of the headlights "wink".
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Thread Starter
Intermediate
Joined: Jan 2010
Posts: 34
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From: nj
A friend said it might be some kind of transmission kick down switch but not sure. We could not figure out how it should be hooked up. In the close up pic you can see its mounted to the firewall with two rivets and a bolt. I don't think it was an aftermarket thing.
Instructor
Joined: Dec 2009
Posts: 109
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From: Nassau co. NY
On one of my older car aquisitions, there was a valve similar to that for a water injection system that was once installed on the car. it was a vacuum operated switch with 2 elect. terminals . I later found out it was a Holley water injection kit. Still kept the switch around in my toolbox.
Good luck.
Greg.
Good luck.
Greg.
Safety Car
Joined: Apr 2000
Posts: 3,802
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From: Wichita KS
Instructor
Joined: Jul 2007
Posts: 245
Likes: 2
From: Hope Indiana
Any chance this car has or did have a computer controlled transmission on it, like a 700R4? The kits to put these into non-computer-controlled cars has a vac operated switch to control lockup.
One example:
http://www.jegs.com/i/TCI/890/376600/10002/-1
One example:
http://www.jegs.com/i/TCI/890/376600/10002/-1
Thread Starter
Intermediate
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From: nj
Torque converter lock-up kit
I think your right nw2571. I did some searching on the internet and on the car and found a few things. Under the dash I found a toggle switch hooked up to a power source and going through the firewall to a green wire that goes into the trans. It looks like it was a torque converter lock-up kit. Im not really sure what it does and not to sure if I should hook it back up. Any thoughts.
Race Director
Joined: Jul 2004
Posts: 12,711
Likes: 329
From: Scottsdale Arizona
I think your right nw2571. I did some searching on the internet and on the car and found a few things. Under the dash I found a toggle switch hooked up to a power source and going through the firewall to a green wire that goes into the trans. It looks like it was a torque converter lock-up kit. Im not really sure what it does and not to sure if I should hook it back up. Any thoughts.
I've never seen the vacuum switch and there shouldn't be a toggle switch (might have been added) but that could be it.
