What do these wires do

[dtkarst]

I’m changing valve cover gaskets on my 71 toldayvwhile it’s ten degrees outside and have always meant to take a picture and see what these wires do. They come from the back of the motor out of these wiring harness that goes down to the transmission and comes to the front. Anyone know what they are?

[Troy Sr]

Could they be the kick down wires from a Turbo 400 automatic Transmission?

[Sheepdip]

What's your transmission? If it's TH400 they could be for the kickdown (passing gear) and would go to a WOT switch on your throttle linkage on the other side of the carb.

Edit: Troy beat me to it!

[68 P.O.S.]

It's probably from the TCS system

Here a thread with some pics: http://67-72chevytrucks.com/vboard/s...d.php?t=649876

[dtkarst]

It is a 400 transmission and a big block. When I bought it the po put a Holley carb on it and I changed it back to the original but don’t have anything else on it. Here’s the carb

[dtkarst]

And could that be why the transmission won’t kick forward and move in drive unless I wrap it up? Or would it be the transmission going out like I originally assumed?

[Sheepdip]

http://www.wiringharness.com/tcs.htm

Hope this helps

http://www.wiringharness.com/images/parts/01114432.jpg

[randy500]

Connector looks like tcs...it’s a separate wiring harness which you can trace back to a round hole in the firewall by the fuse panel.

You have the transmission kick down wiring in the firewall above the windshield washer hoses, pink or orange wire next to the oil pressure line, inside it should hook the the pedal switch, outside. should hook up to the trans. You should be able to hear the solenoid click if under the truck and someone pushes the pedal to the floor.

[randy500]

And that empty hole above the distributor hard line on the carb should have a metal tube it for the distributor...open like shown is a ported vacuum leak.

[68 P.O.S.]

TCS doesn't actually affect the shifting. It was an early, crude form of emissions control that restricts the vacuum advance from coming in until the engine is fully warmed up and you are cruising in high gear. It no longer serves any good purpose and you can remove the whole system.

[dtkarst]

It is a 400 transmission and a big block. When I bought it the po put a Holley carb on it and I changed it back to the original but don’t have anything else on it. Here’s the carb

[dtkarst]

Originally Posted by randy500

And that empty hole above the distributor hard line on the carb should have a metal tube it for the distributor...open like shown is a ported vacuum leak.

Which part are you talking about?

[randy500]

Originally Posted by dtkarst

Which part are you talking about?

Sorry, I see the tube now, background obscured it when i first looked

[Doug's68SS]

if you are having to rev up the motor to get the truck to move I would start by checking the fluid in the transmission. if that is good you have a transmission problem.

[dtkarst]

Yeah I have good fluid and everything, I was just holding out hope I wouldn’t have to change it lol