No heat/defrost 01 corolla

when I saw this question last night, I thought to myself 130' seems awfully low!

Correct Operating Coolant Temp

Toyota Nation Forum https://www.toyotanation.com > threads > correct-oper...
Jan 26, 2021 - It should be around 185-190F. Buying OEM, it usually comes with a gasket. You'll need to drain the coolant, so it's a good time for a flush.

I think you have air in the cooling system, perhaps even a stuck thermostat, or a heater valve that isn't opening. Start with burping all the air out.

https://www.fixya.com/cars/r29872074-vehicle_cooling_system_no_heat

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I found this on Toyota Nation Forum: "Yes, it should take an engine 5 to 10 mins. to get to operating temperature, 190deg in your engines case.
If it takes longer then thermostat needs to be replaced, for sure.
The thermostat controls the minimum operating temperature of an engine.

So I would drain coolant, reuse if not too old, and change thermostat, make sure new thermostat has a "jiggle valve", and you install it with "jiggle valve" at the 12:00 position.
A "jiggle valve" is a hole in the t-stat plate that allows air to escape when refilling the cooling system, it has a metal pin in the hole that "jiggles" to prevent hole from being blocked by debris, which is why it is called a .............jiggle valve

Green coolant needs to be changed every 2 years.
Red coolant needs to be changed every 5 years.
Do not switch from Green to Red or Red to Green, stay with what you have, which should be Red/Pink.
The anti-freeze component in coolant never wears out, the anti-corrosion compounds do, which is why it is important to change coolant when specified.

Back flushing the heater core is always a good idea, the heater core has the smallest passages in the system, so any debris will find its way there and if large enough stay there, over time the core passes less hot coolant so max. temp inside car can go down.
Back flushing means you will reverse the flow in the core, and hopefully push any larger debris out the way it came in.
Regular flushing doesn't do this.

Google: back flushing heater core video

The make and model don't matter, method is the same on all vehicles, you can use air or, what I use, a garden hose, after first back flush I also fill core with a warm mixture of CLR and let it sit for 20 min. then back flush it a few more times.
I then fill it with coolant before reattaching the hoses."

I hope this helps you!

Most of the times the heater core gets clogged or corroded. inside the fire wall and the hoses run through the engine compartment and into the firewall. You can try disconnecting the top and bottom hoses and using a garden hose to flush out debris. Flush through top hole first then bottom cycle back and forth to break everything up and water comes out clear. Then hook the hoses back up. Also make sure that your radiator l with coolant at the proper level. The heat typically coming out warm then blowing cold is low coolant or clogged heater core but the gauge on the dash should only symbolize engine temp. If it stays on cold, you may also want to check your thermostat to ensure it functions and opens and closes as it should. All cheap fixes that can be done yourself.

the most affordable thing to do is either flush radiator and change thermostat.and see what happens the other thing is your heater core is clogged or is no good

is it flowing into the heater core check line at heater core when engine is warm hoses should be warm as well if they are not its possible thermostat is stuck.

Try flushing the radiator and/or changing the vented cap. If that's no help, you may have a faulty thermostat or heater core.

i don't know realy if there is a fuse (though i doubt it) but issues with heatting may be this will help.

If the carpet under the heater core is damp, or if antifreeze vapor or steam is coming through the vents, the heater core is leaking.
Remove it and install a new unit (most radiator shops will not repair a leaking heater core.
If the air coming out of the heater vents isn't hot, the problem could stem from any of the following causes:

• The thermostat is stuck open, previnting the engine coolant from warming enough to carry heat to the heater core. Replace the thermostat.
• There is a blockage in the system, Preventing the flow of coolant through heater core. Feel both heater hoses the firewall. They should be hot.if one of them is cold, there is an obstruction in one of the hoses or in the heater core,or the heater control valve is shut. Detach the hoses and back flush the heater core with a water hose. If the heater core is clear but circulation is impeded, remove the two hoses and flush them out with a water hose.
• If flushing fails to remove the blockage from the heater core, the coremust replaced.
  

If u have issues with heatting may be this will help.

1- If the carpet under the heater core is damp, or if antifreeze vapor or steam is coming through the vents, the heater core is leaking.Remove it and install a new unit (most radiator shops will not repair a leaking heater core.

1 - If the air coming out of the heater vents isn't hot, the problem could stem from any of the following causes:

• The thermostat is stuck open, previnting the engine coolant from warming enough to carry heat to the heater core. Replace the thermostat.
• There is a blockage in the system, Preventing the flow of coolant through heater core. Feel both heater hoses the firewall. They should be hot.if one of them is cold, there is an obstruction in one of the hoses or in the heater core,or the heater control valve is shut. Detach the hoses and back flush the heater core with a water hose. If the heater core is clear but circulation is impeded, remove the two hoses and flush them out with a water hose.
• If flushing fails to remove the blockage from the heater core, the coremust replaced.
  

remove the heater core lines the two hoses that go to the heater core, take a splice tube either metal our plastic your part store will have either one. take the splice tube and install it in one of the lines add some hose to that tube make the hose long enough to run out side of the engine compartment and on to the ground. take the other hose and install a flushing tee, hook up to a garden hose and trun the water on . what you are trying to do is flush the heater core , you are also looking for blockage off the heater core, if you little to no flow i would suggest replaceing the heater core

dude i dont know too much about toyotas but the same thing happened to my 87 firebird and it turned out to be the heater core in the end. i suggest taking a look couldnt hurt