What are the high pressure lines under the dash?

So when getting out of my truck a couple days ago I finally couldn't stand the beeping. I grabbed a flashlight to track down the piezo. I rested my hand on one of the lines that look like A/C lines under the dash and they were so hot that it burned and has blistered. It seems strange to have lines that get that hot inside the cab. Anyone know what those are? I will look when I am back under there. Just seems odd.

 

Not sure where your hand was, but there are coolant lines under the dash for the heater core.

 

Under the drivers side. I am guessing that it was AC, but seems weird to have the expansion valve inside so that the hot line is in the cab. It was HOT with AC on.

 

Sounds like you were reaching around the heater core tubes.

 

The speaker is on the back side of the instrument cluster. If you remove it, you will lose the turn signal sound also.

 

i disabled all beeping via the head unit when i first got my truck. don't remember how but used the owners manual to do it.

 

The expansion valve is going to be cold anyway. The liquid solenoid valve would get warm. And even then, not blistering hot. Maybe a heater core line. The heat will stop at the hot water valve, but will use the heat to dampen the cold so you don’t freeze to death. The heat will always be there for instant temp modulation.

 

^This

^And this.

 

I will try through the head unit first, but losing turn noise is a fair trade off. So. Much. Beeping.

 

Agreed. I have it down to just the key in chime, of course with the turn signal sound. That is livable to me.

Some settings are in the head unit, but the big ones are done with Tech Stream or the Carista app, such as the seat belt chimes.

 

In order for AC to work it needs a compressor, the compressor turns the refrigerant really hot

Edit: besides the AC coil is under the passenger side, not the driver

 

Not necessarily really hot. It compresses and condenses it. Sheds the heat, then expands into the evap core.

 

I work on AC units, the lines directly off the compressor can get really hot from time to time

 

Same here, inadvertently. It’s an ambient temp thing, even in 1ton mobile systems they don’t get blistering hot. But you do have a “hot” side, and a “cold” side, so to speak.

In other words, the only thing that hot in the cab should be the heater core lines.