dennisr

The turbo 400 I removed from my 71 had an electrical plug on the driver side that was connected to two wires. Does anyone know what these wires are for? One is orange, one is black.


[Modified by dennisr, 7:43 AM 8/6/2001]

Smokehouse69

Those wires attach to the kick-down solenoid. There is a switch on the accelorator linkage that is closed on full throttle, when the switch is closed it routes 12volts to this solenoid and downshifts the transmission if it is in the right range.

blue72

Are you sure that isn't the reverse switch?

Jvette73

The wires going into drivers side of the TH400 are for kickdown.

The reverse lights activate from the nuetral safety switch mounted on steering column, i think.

Smokehouse69

The reverse light is inside the shifter console. It is a combination switch that does neutral safety and reverse light functions.

JimD

Are you sure this is the kickdown switch? On my 71 I noticed it was unplugged when I was under there but while it was unplugged I had no problems with the transmission down shifting. I think the wire is for the TCS (Transmission Controlled Spark) solenoid. I don't know what this is supposed to do though. I plugged it back into the transmission and the car didn't run or shift any different.

Smokehouse69

Jim,
It could possibly be something to do with the TCS system my car doesn't have one they started TCS in 1970. I looked at my car last night and saw that on the 69 there is only 1 orange wire to the kick-down, the solenoid is located on the driverside of the transmission right behind the shifter input shaft and infront of the speedometer cable. The ground is provided by the case itself.
I'd suggest looking at the wiring diagram, to verify what it is.

Jvette73

As far ar I know, all TH400's kickdown is controlled by electric solinoid mounted at the edge of the valve body. If thats the only wire leading to the tranny then its got to be for kickdown.
Jim, I thought my kickown was working but found out otherwise. The fact is, tranny kickdown can also be actuated by the vacuum modulator. Mine was anyway. I would be cruisin along in 3rd gear at 35mph and then punch it to the floor. The car would kickdown into 2nd. The vacuum mod was controlling that kickdown. After fixing the electric kickdown set up, under those above conditions, the car would kick from 3rd to 1st, and really throw you back in the seat. I suggest to everyone that even though you may feel a kickdown, that doesnt mean that the electirc kickdown is working.

Tims75

If you have a service manual you can check the wiring diagrams for the section and that will let you know exactly where they go, which will then tell you what they are for.

On my 75 I have the one orange wire for the kickdown, too.

Tims75

blu73

I think you will find that one of the wires is for the TCS, and the other for the kickdown. I looked into this some time ago and even wrote a letter to Corvette Fever about it. My '73 only has the orange wire. It looks like there was never a black one and I tried to find out if there were some conditions back when the car was built that would have let it be built without the TCS hardware in place. Unfortunatly, I missed the issue that had a reply to the question, so I never did find out what might have gone on.