New Game of: What is This Part?

Would appear to be a relay of sort.
Note: I have battery quick disconnect. When I reconnect the battery, even with the key off, it clicks on.
If I leave it it gets fairly warm.

Any ideas?
Thanks

 

temp sender?

 

Hard to see in your picture, but I would guess TCS (transmission controlled spark) switch.

 

It's an electrically actuated vacuum switch. Part of your temperature controlled spark (TCS) system. The idea (as I recall) is that under certain conditions the vacuum advance will be inhibited to reduce NOX. The system inputs are coolant temp and transmission gear. Here's the basic logic:

System wants to inhibit vacuum advance to reduce NOX. However, inhibiting vacuum advance will make your engine a dog, especially when it's not up to operating temp. Also, when you're not in high gear you most likely want all of the power you can get for passing cars (is there anything slower than a Jeep?) or pulling a hill. So the system compromises by only inhibiting vacuum advance when the engine is up to normal operating temp and when the tranny is in high gear (i.e. you're cruising so you probably won't notice the power loss as much). If you yank all that stuff off you may notice some improvement in power under the following conditions: engine at normal operating temp, and tranny in high gear. Performance otherwise will be unaffected. Tim can audit my thesis and correct, I'm sure.

Chilly


Added: the vacuum line isn't connected so yours isn't functional at this point.

 

Thanks guys.

Here's a close up if it helps.

Could I just remove it, I'm assuming so since its not hooked up, and its not like its going to screw up the onboard computer
But it seems to use juice and get hot.

 

Chilly's explanation is right - but I'm sure it's not connected to the engine temp in '73. There's a switch on the transmission top that goes with it.

Yeah, you can remove it unless you want/need to keep the emissions gear in place. I believe the system will have its own wiring harness that you can remove in its entirety. Leave the switch in the transmission to plug the hole.

 

The vacuum line on my 73 runs from the switch shown in the photo through a thermal switch screwed into the intake manifold, then to the vacuum source. The electrical connection is in no way interfaced to engine temp, but the vacuum line does indeed route through a temp switch. I think the 1973 FSM also shows some ambient air temp sensors and some vacuum accumulator do-dads but those are missing from my grille. No matter, I'll be getting rid of the whole system when I get it on the road.

 

Alright, thanks guys.
It will be disconnected shortly :smash:

Also, as you suggested Tim, their is a harness spade plug to easily disconnect it.

Here in rural TX they honk the horn, check the lights, and make sure it stops - end of inspection.

 

Pretty sure the thermal switch (CTO) only controls the source of engine vacuum depending on temperature, and does not provide any signal to the TCS. IIRC there is a 2-nip and a 3-nip CTO; the 2-nip turns EGR off when the engine is cold. The 3-nip provides manifold vacuum for the vacuum advance when cold (for better cold-start performance) and switches to ported (carburetor base) vacuum as the engine warms up. The only signal the TCS gets is electrical, from the transmission top switch, which closes the valve in top gear.