3rd and 4th gear pressure switches

[Brooks]

Does anybody know if the 3rd and 4th gear switches are normally open (NO) or normally closed (NC) switches?

Charles Brooks

 

[2quiktocare]

Both switches are the same part number and both are open and close the curcuit when pressurized.

Mark

 

[Brooks]

Thanks Mark

 

[S10xGN]

Originally posted by 2quiktocare
Both switches are the same part number and both are open and close the curcuit when pressurized.

Mark

Mark, are you sure? A long time ago I was looking to use these inputs for something, but gave up after finding out that power was "dropped" when the gear engaged. Woulldn't that make it a NC switch?

 

[Sleeper]

Originally posted by 2quiktocare
Both switches are the same part number and both are open and close the curcuit when pressurized.

Mark

Mark, you need more coffee
I think you got things backwards, as Russ pointed out. The switches are NC and open when pressurized in 3rd and 4th.

Paul

 

[2quiktocare]

Well, I know that the switches are open (meaning no complete curcuit) without pressure, and closed (meaning the curcuit is complete) when we apply 23 to 24 pounds of pressure.

Mark

 

[Sleeper]

Originally posted by 2quiktocare
Well, I know that the switches are open (meaning no complete curcuit) without pressure, and closed (meaning the curcuit is complete) when we apply 23 to 24 pounds of pressure.

Mark

Sorry Mark, but I have to disagree.
I run a hybrid, and had to do most of the ECM wiring from scratch. When it came to setting up the tranny wiring, my switches were N/C.
http://www.gnttype.org/techarea/images/wiring_images/ecm_turbo.jpg
Take a look at the lower right side of the diagram.


Paul

 

[2quiktocare]

From what I see, the switches are marked open at rest. The diagram even list them as being open if I am not seeing things.

Mark

 

[WE4]

OK.. Sleeper is correct

The 3-4 switches stock in a 2004r are normally closed. As pressure hits them at around 35 psi, they open. Mark asked me the other day and I misunderstood what he was asking.
I thought he meant when we have no computer, like in a conversion, what switch is used. For that application, a normally open switch is used. They close with pressure.
But in stock form with stock computer they are NC till it sees pressure. then they OPEN.
My bad for missing what he was asking me.

However, we will all wake up tommorrow morning so this is a good thing


Bruce
WE4
www.PTSXTREME.com

 

[Sleeper]

Hey Bruce
Thanks for clarifying.

Paul