1970 LS-5 tcs switch lead

[Chris H.]

Re: 1970 LS-5 tcs switch lead

Better photos. Hard to believe the factory "tidy-ness".


IMG_1092.jpgIMG_1093.jpg

[Monte M.]

Re: 1970 LS-5 tcs switch lead

Now that we have resolved this matter, thanks Chris, does anybody have a picture of where the jumper actually plugs into the main harness?

[Eugene V.]

Re: 1970 LS-5 tcs switch lead

Chris,

Thanks, that is what I was looking for.

Monte,

Thanks for your help. I was under the impression that I wasn't being clear about which TCS switch I needed the info about.

I do appreciate your help,

Gene

[Terry M.]

Re: 1970 LS-5 tcs switch lead

Chris,

Thanks, that is what I was looking for.

Monte,

Thanks for your help. I was under the impression that I wasn't being clear about which TCS switch I needed the info about.

I do appreciate your help,

Gene

Perhaps I was the only one who lacked clarity. Sorry.

[Patrick H.]

Re: 1970 LS-5 tcs switch lead

Could be.

I should see if I have the original from one of the cars and verify length.

I compared the original from the orange 72 small block to the current reproduction as both were in the spare parts box. The original line did not have the white tape that is on the repro, but who knows what may have happened in the last 40 years.
However, overall length laying them next to each other was not significantly different. The repro was longer, but not enough to explain all the amount bound up by the tape. And, no series of kinks in the original that would show it had been looped/folded like the repro.

So, I suspect that Gene could use a repro harness without worrying excessively about length. He may have to remove the tape given the different location of the temp switch in the head of a big block vs small block, but that's up to him. And, as Terry noted, he could likely shorten it if he wanted to.

Does the AIM happen to show any routing details of the green wire? One would think it would be there. I just searched my 1971 AIM as it's the one here in my office and see nothing shown for any of the motors.

Patrick

[Monte M.]

Re: 1970 LS-5 tcs switch lead

Terry,
I was a little confusing at the beginning. Then I finally figured out it was not the TCS switch he was talking about.

I think Gene may still be a little mixed up in why there was any question as he is still calling the heat sensor the TCS switch.

Gene, you initial question might have been, "Does anyone have a picture of the heat sensor on the passengers head that the wire goes up to the TCS switch on an LS-5 with the wire still attached?"

This question would have resolved the issue much sooner. We all learn each day. At least I do.

Monte

[Craig H.]

Re: 1970 LS-5 tcs switch lead

I would venture a guess. It is that long so the vendor can sell the same part to folks with cars with much larger engine compartments -- say Chevelle or other A-body cars, or full size Chevrolet (B-body) or who knows maybe even Cadillac.

When I was looking into the CEC/TCS on my SB 71 I also wounded why the final lead was so long.

After pulling it all apart including the timer relays etc so I could see how they worked and consulting with a friend who is very well versed in designing circuits we came to the conclusion the length is most likely to create a specific resistance in that part of the circuit.

Covered here

http://forums.corvetteforum.com/c3-g...journey-2.html

[Monte M.]

Re: 1970 LS-5 tcs switch lead

Gene,
I know it is a little late and it is the wrong year, but here are a few pictures of a 72 from a few years back.

Edit: After looking at it, this is not my 72. No A/C

[Eugene V.]

Re: 1970 LS-5 tcs switch lead

Patrick,

Thanks for your effort.

I could not find anything in the 1970 AIM either, but I will look again. I would guess that since the harness was installed as an assembled unit there would be no need for separate instructions to install that jumper.

The jumper that I have has a very small loop of wire at the plug and no tape at the plug as in the above photo.

Thanks again for your help,

Gene

[Doug J.]

Re: 1970 LS-5 tcs switch lead

Gene,
Do any of these picture's help? There from a 1971 LS-5. I usually keep it tucked behind the relay but took it out for the picture. The green wire lead goes from the temp. sensor to a connection coming out of the main harness with a green wire also.

[Eugene V.]

Re: 1970 LS-5 tcs switch lead

Doug,

Yes they do. Thanks for your help

Gene Ventura

[Monte M.]

Re: 1970 LS-5 tcs switch lead

Doug,

Great pictures.
Can you get a picture of where it plugs into the main harness? Is it a dark green wire that it plugs into?
If you cannot get a picture, can you describe, to the best of your ability, exactly that plug is.
Is it attached to a single female black wire clip?

Thanks,
Monte

[Doug J.]

Re: 1970 LS-5 tcs switch lead

Monte,

The second picture shows the green wire coming out of the main wiring harness, if you look at the bottom of the picture you can see a little bit of the connector..it is a female end. In the last picture, the wire I am holding is the wire coming out of the main harness, you can see the entire connection. The end of the wire lead that plugs into the main harness is a male end. So the end of the green wire lead that goes from the temp. sensor really can't be confused with the other end ..which is a male end....two completely different types of connections.

Hope that all helps......Doug

[Terry M.]

Re: 1970 LS-5 tcs switch lead

Not every 1970-1972 has that extra harness shown in the first photo posted by Monte. Some have the green single wire coming out of the harness with no connector until the 90* double connector on the end. When we were researching this feature for the 1970-72 TIM&JG a decade ago our first thought was that small blocks got the extra harness and for large motors the wire went direct to the temperature sensor -- but that proved not to be the case.

If you were the line worker making this connection wouldn't the extra harness be an advantage on small blocks? That extra harness could be put on the sensor on the engine dress line when the spark plug shields were installed; and then a simple connector out in the open could easily be made up when the body drop occurred. Large motors would be no issue for the connection at the sensor at body drop because of the sensor's accessibility. Oh if life were so simple.

Of course now that all replacement wire harness have that single connector and the extra harness – we will never know the real answer. The horses have left the barn.

[Monte M.]

Re: 1970 LS-5 tcs switch lead

Terry,
Thanks for chiming in. I am having trouble finding the wire where it seems to come out of the harness. I have had this 72 for quite a few years. In all these years I have only found three wires that came into question at all.

One has been trying to find the end that the heat sensor jumper would plug into. There are no wires cut anywhere. I could cut the jacket/tape from the plug at the TSC solinoid and follow it until I find the end of the wire, but that is not option one. If anyone has an idea where exactly I might look for that wire, (the one the TCS jumper would plug into if I were to use a jumper) it sure would help.

EDIT: The wire does not go to the relay on the outside of the evaporator, it goes the relay that clips on the vacuum hose of the wiper actuator.

The second issue is a black wire that comes out of the main harness about two inches below where the tach cable comes out of the firewall.

The third issue is where the single green wire that connects to a relay that clips on the vacuum hose of the wiper actuator, and the other wires go to plug into the POA valve, the clutch, and the back of the compressor. Where that single green wire originates is the question. My A/C works fine, but I think that wire is hooked up wrong.

I do not want to hijack this thread with my questions, so if you have an answer, you can PM me if you like.

Any ideas where the jumper plug might be would be appreciated.

Monte