1970 TCS component help....again

[James W.]

Hello all....First time poster, long time lurker! Well, assuming my photo's will upload, here is my question. On the firewall, to the left of the windshield wiper motor is the TCS relay. The relay in my case has a connector with two green wires, one of which has been cut. If my photo works, and if it's clear enough, you can see the connector with the cut wire just to the right of the distributor shielding, and further below, just under the red lined hoses, there is the end of a greenish colored cut wire sticking up out of what appears to be a main harness. Does this stub of wire go to the cut lead coming off of the connector above? It seems logical, however the stub of wire coming out of the harness looks a little darker than the wire off the connector? Anyone have a photo of the same area unmolested?

Additionally, thanks to your tech board, I got the diagram of the vacuum routing off of Doc Rebuild's site, so thats taken care of. I found the electrical lead (intact) that goes to the TCS solenoid, and the TCS switch on the left side of the transmission seems intact. It has a single black wire that disappears up into the firewall area. Where does that wire end up connected to? Finally, can any one show me a photo of the TCS sender in the cylinder head, and how, and with what, is it connected to?

Now before anyone asks, yes I have the assembly manual, service manual, several restoration books, and the NCRS technical guide. It seems that in all of these publications, at most, the TCS system is barely mentioned, and photos of it seem non-existent. I was able to get one decent photo of the system (passenger side of engine, without air-cleaner) off NCRS archives, but that was about it. Anyway, I would certainly appreciate any help, photos, etc anyone could provide, Best Regards, James Williamson

[Pat M.]

Re: 1970 TCS component help....again

Hi James, Welcome!
Here is a pic of the TCS relay wiring on my 70 350/300. As you can see, one of my wires is green and one is blue, and they both disappear into the wiring harness.
The second pic is of where the temp sender unit goes into the engine near the passenger exhaust manifold, although you can't see the unit itself due to the shielding that I was too lazy to remove at this hour!
But I can tell you that the unit is screwed into the head, and as you can see a green wire comes out of it, and I'm not real sure of where the wire goes.
Sorry I can't give you much technical info, but I hope the pics help.

[Steven G.]

Re: 1970 TCS component help....again

The relay has 3 terminals, rear (single) is black with white tracer, top (front) is green and bottom (front) blue, all going together to main harness. The lower cut wire must be blue and top cut wire off relay is definately blue. A tip, black wires with white tracers are different solid black wires, a close inspection of tcs (trans. sw.) wire, may be required, wire colors can change when exposed to vehicle operating temperatures. Steve

[Terry M.]

[Jack H.]

Re: 1970 TCS component help....again

Terry is correct. The 'thingy' that's in the RH rear cylinder head is NOT a temp sender...it's a thermal switch (SPDT configuration). It monitors and reports engine temperature to the TCS controlling relay.

It's status is closed (contact closure to ground) when the engine is below normal operating temperature, open closed circuit when the engine is at normal operating temps, and closed when the engine is above normal operating temp. That's why there are two plug-in terminals on the switch (one for low temp, the other for higher than normal temp) and the wiring harness has a single green wire that 'daisy chains' the two at the connector.

[Dennis D.]

Re: 1970 TCS component help....again

Hello all....First time poster, long time lurker! Well, assuming my photo's will upload, here is my question. On the firewall, to the left of the windshield wiper motor is the TCS relay. The relay in my case has a connector with two green wires, one of which has been cut. If my photo works, and if it's clear enough, you can see the connector with the cut wire just to the right of the distributor shielding, and further below, just under the red lined hoses, there is the end of a greenish colored cut wire sticking up out of what appears to be a main harness. Does this stub of wire go to the cut lead coming off of the connector above? It seems logical, however the stub of wire coming out of the harness looks a little darker than the wire off the connector? Anyone have a photo of the same area unmolested?

Additionally, thanks to your tech board, I got the diagram of the vacuum routing off of Doc Rebuild's site, so thats taken care of. I found the electrical lead (intact) that goes to the TCS solenoid, and the TCS switch on the left side of the transmission seems intact. It has a single black wire that disappears up into the firewall area. Where does that wire end up connected to? Finally, can any one show me a photo of the TCS sender in the cylinder head, and how, and with what, is it connected to?

Now before anyone asks, yes I have the assembly manual, service manual, several restoration books, and the NCRS technical guide. It seems that in all of these publications, at most, the TCS system is barely mentioned, and photos of it seem non-existent. I was able to get one decent photo of the system (passenger side of engine, without air-cleaner) off NCRS archives, but that was about it. Anyway, I would certainly appreciate any help, photos, etc anyone could provide, Best Regards, James Williamson