70 TCS Temp Sensor Wire Connection

[Pat M.]

Hi everyone. How are the two wires coming from the two-pronged TCS temperature sensor on my 1970 supposed to be connected? The pink wire on mine is simply cut off near the sensor.

Pictures I have seen seem to show the two wires connecting in some fashion and exiting as one large green wire. But I can't determine exactly how they are connected, and I've found only veiled references to a "bridge" in the archives. Thanks for any help, Patrick Moresi #45581

[Chuck S.]

Re: 70 TCS Temp Sensor Wire Connection

Hmmm...Patrick, are you sure it's the TCS jumper harness? The link below (VIG7074TCS) shows a single green wire, and the temp sensor is grounded in the engine block...it wouldn't need a ground wire.

I thought I remembered two flat terminals, but the harness doesn't show it.




Lectric Limited TCS Jumper Harness

[Pat M.]

Re: 70 TCS Temp Sensor Wire Connection

Hi Chuck. Notice how in the harness in your link one wire from the sensor plug simply routes over and connects to the other wire - and they both exit as one large green wire.

I think you're right that the sensor doesn't need a ground wire, and I don't think either wire is a ground. I think each wire sends a signal to override the TCS (and allow full vacuum in all gears) - one wire when the engine is too hot, and the other wire when it's too cold. But apparently either signal eventually travels down the same single green wire.

But this brings me back to my original question - are the two wires simply spliced together?

Thanks for your response, Patrick Moresi #45581

[Harmon C.]

Re: 70 TCS Temp Sensor Wire Connection

Patrick

I have seen the plug with a small loop of wire from one side to the other then only one wire goes to the harness so they are hooked together on one of the spade terminals. It may be the same on a 70.
Lyle

[Terry M.]

Re: 70 TCS Temp Sensor Wire Connection

There is a short green jumper wire that connects both terminals, and both those connect to a longer green wire (all wires are the same diameter). There is a small piece of black tape (same style as the tape on the vacuum lines) holding all three wires together. There are no pink wires going to the TCS temperature sensor.
Your analysis of the electrical operation if correct.

[Pat M.]

Thanks Guys ...

So the two wires must connect to the same spade terminal.

Terry - I don't know why, but the jumper wire on my plug (most of which is cut off) is a smaller diameter than the long green wire, and it's pink. I know my wiring harness is original, so somewhere along the line it must've been fitted with an incorrect plug and/or jumper wire.

I really appreciate everyone's input. Patrick Moresi #45581

[Chuck S.]

Re: 70 TCS Temp Sensor Wire Connection

OK, Patrick, now that ya'll have described the harness, you can see the short jumper loop and the black tape that Terry describes in the link picture...check it out; the jumper loop is longer than I would have expected and connects both sides of the terminal connector. Interesting.

[Terry M.]

Re: 70 TCS Temp Sensor Wire Connection

I agree Chuck. the jumper in the illustration looks longer than I remember mine, and the ones I have judged as well. On SB it doesn't matter too mch because most of the temperature switch wire is inside the chrome spark plug shield, and out of site. It is the BB that has it all out there for everyone to see.

FWIW: Not all the original wiring has the seperate harnes for the TCS switch. That is some cars don't have a connector for the temp harnes -- it is hardwired into the engine compartment harness. Years ago we tried to figure out if this was related to a particular engine or transmission without success. Some just seem to be hardwired into the engine harness.

[Chuck S.]

More Good Info...Thanks!!!

If I'm not mistaken, I don't remember there being a jumper harness connector on my engine harness either, but it was pretty messed up over on that end. I remember seeing the TCS jumper harness in Lectric Limited's catalog, and wondering why I needed that...I bought it anyway.

[tom444634]

Re: Thanks Guys ...

Patrick,

Below is a picture of the one on my 71 (early Sept 70 build) LS5.

The wires are dark green and as you can see, the extension wire is about 6" long. The plastic connector housing is MIA.

Tom

[Pat M.]

Re: Thanks Tom

Thanks so much, Tom. Can't get much clearer than that.

Patrick Moresi #45581

[Terry M.]

Re: Thanks Guys ...

I am told that the plastic connector for a turn signal flasher is a suitable replacement for the melted plastic TCS temperature connector. I have no personal experience with this substitution, but you may find it worth checking out.