Heater not working after radiator switch, engine coolant temperature gauge also not working

Going to check all of that now. Feel I should note the gauge did move after an hour of driving around. A tiny amount in the picture. There has to be some issue with the wiring between the gauge and the computer?

Image.

Okay, at temperature the heater core hoses were warm and flowing.

I did replace the coolant temperature switch. I don't have good pressure in the lines though. Any of the radiator lines. Wondering if the thermostat is stuck open? I have a replacement but know getting at the housing is difficult. And I've already blown through way too much coolant I'd rather not have to buy another 3 gallons.

I did some testing on the wires for the temperature gauge problem. The connector to the temperature gauge switch on the passenger side of the radiator hose has almost no power to it when it's connected to a test light it barely shows but not bright like it should. Does this indicate that the gauge itself has gone bad or that the wire has gone bad or rather the connector at the wire in the engine bay? Please advise. Will be checking the blend door as soon as I can get the front panels off I spent most of the good part of the sun today painting the truck bed with bed liner.

I am referring to the yellow and violet/purple wire that I've seen on a couple of forum posts connects directly to the gauge, supposedly. Unsure I have a 96 v6 Magnum. And there's no post for that specifically I found one video set on the temperature gauge for an 88 v6 Magnum but it's a totally different connector.

After a small amount of silicone WD 40 the gauge reads maybe 20 percent better. Still not fully correctly but as though some of the excess resistance was at the connector (extremely dirty).

Still unsure but the heater issue was marginally better when the gauge read at a higher temperature. Are they systems connected? Next week I will be replacing thermostat (I think is stuck open) thermostat housing, and flushing the heater core while I'm in there. Can't hurt hoping that the thermostat being stuck open is part of my heater issue. I had read that it flows coolant too quickly through the heater core. Could be wrong. Could have a blockage, could be the gauge itself. Have to junkyard for a replacement in case.

Shaft is moving can't locate the blend door actuator. Unclear what need to be removed next.

This is the Console box and it's moving properly.

So it isn't the black cable attached to the arm? I don't see a cable running from that piece in particular. Will I need to remove the box?

I want to say it is working and it's a core issue. I get good heat when the fan isn't on. I have a chemical flush now and will do the full system flush and a core flush ASAP. Hopefully that fixes the heat issue.

Still confused on the gauge.

Okay, final update for me.

Drained, and used a chemical flush. Then drained again and back. Flushed the heater core. Not dirty but good to know.

In replacing the thermostat and housing I was right in that the thermostat was locked open. Thus causing the cascade of issues.

New gasket, new thermostat and a mistake of a spill on my part later and it's filled burped and everything works again.

Heater is easily twice as hot as before. The temperature gauge works again properly.

Worth doing the checks and appreciate the help but regular maintenance is regular for a reason.