What are these two tiny wires, each with a single-terminal round pin?

[AlaskaFestivaGuy]

See photo. Ends I found not connected are draped across battery.

This car (89LX) stumbles badly -- could this be a factor?

On my only other complete LX here (which also stumbles), what might be the same two wires are connected somewhere down in the darkness.

[WmWatt]

They both plug into the bottom of the radiator. It looks like a temperature sensor down there.

[AlaskaFestivaGuy]

My 89LX radiator doesn't seem (as best I can see/feel) a temp sensor, which would explain the wires just hanging there. Its radiator does have some extra fittings on the bottom, so I suspect it might be from an automatic, which I think I've read has a built-in little oil cooler below the regular radiator.

What are the implications of having these wires hanging in space? The radiator fan runs based on a coolant temp sensor on the engine, right? Is there any chance this would cause or contribute to severe stumbling when driving with minimal load (e.g. doing 30mph on the flat in 4th)?

[WmWatt]

I've read the radiator fan is wired to come on if the current drops. Need current to keep it from running, like the dead man's throttle on a motorcycle or outboard engine on a boat. Don't know the implications for your beast. A search of the forum might bring up more info, say "radiator thermostat".

[AlaskaFestivaGuy]

This seems to explain everything:

https://fordfestiva.com/forums/showthread.php?39252-Temperture-Gauge-Sensor&highlight=radiator+thermostat

There are FOUR temp sensors:
1. The one on the radiator activates the carb heater.
2. The one on the thermostat activates the fan.
3. One on the block feeds the ECA.
4. Another one drives the in-dash temp gauge.

The above post (entry #6) even specifies wire colors! The poster's XFSE71 profile says he's here in Seattle, but last logged on back in late 2013.

[WmWatt]

First I read about a carb heater. Thanks.

[AlaskaFestivaGuy]

I learned about carb heaters years ago on my first flying lesson.

https://en.wikipedia.org/wiki/Carburetor_heat

Airplanes redirect air around the exhaust pipe into the carb to heat the air. It looks like the Festy electrically heats the carb body.

[zoe60]

Oxygen sensor needs to be good on feedback carbs. Best thing would be to replace it with an Escort carb and a rocketman adapter. More power and will will run better.