The solar sensor, which is installed on the upper side of the instrument panel, detects sunlight and controls the air conditioning AUTO mode. The output voltage from the solar sensor varies in accordance with the amount of sunlight. When the sunlight increases, the output voltage increases. As the sunlight decreases, the output voltage decreases. The Air Conditioning Amplifier detects changes in the output voltage from the solar sensor.

Read more: https://www.autocodes.com/b1421_toyota.html#google_vignette

 

Thank you for sharing post, i went through that post earlier and have tried nearly every possible way to make ac run but wasn't successful. I can try to replace the sensor on dashboard as it comes up in obd scanner as faulty, but not sure if i have to take off the whole dashboard off. I wasn't able to find any helful video on internet on changing solar sensor on this vehicle.

 

does the AC work in manual mode?

 

No, it does not work in manual mode. The only time it worked was in winters but codes of solar sensors were still there.

 

I wonder if this helps. Lookit:

 

I have replaced the solar sensor the one round sensor only sticking out of the dashboard with a new one, but still same codes b1421 and b1424 solar sensor circuit driver side and solar sensor circuit passenger side.

can someone tell that if this sensor is responsible for both driver and passenger side circuit ? Are there another sensors under dashboard ?

 

Replace your serpentine belt. It's potentially slipping.

 

Don't believe that the solar sensor fault will stop a/c from turning on.
For starters need to verify if power is being applied to a/c clutch.
If not then check wiring diagram for test points.

 

Ac was working every time i pressed ac button in winters while the codes were still there. What things can affect the working of ac in summers ? Power is coming to clutch, checked already. Refrigrant is in the system and cools great(was checked in winters). Considering it was working good in winters, i cant figure out what could get wrong.

 

OK, if power is at the clutch( check using a light bulb that draws around 5 amps).
This to insure that circuit is good since clutch may require as much to pull in.
If circuit good then clutch should pull in if electrically good and installed correctly.
Verify clutch electrical resistance and installed gap.
Sorry don't have specs for you right off.

Heat can cause intermittent electrical operation of the clutch.

Let us know how it goes.

 

interesting.
normally a slipping belt will make a noise but, i im no longer surprised when things dont do what their supposed to...

iirc a blinking AC means the engine and AC compressor speeds do not match.

could be a slipping clutch.
could be a slipping belt.
could be a a bald belt, or a tensioner, or pulley.

idk

 

Serpentine belt is brand new. Still same error codes. Anyone knows the resistance needs to be on sensors ?

 

Any idea on clutch resistance ? How can i check ac amplifier ?

 

Just checked resistance, it is a six pin connector with 5 wires, 2 wires red and black for flow sensor, resistance measured at 2k setting is 0.12 ohm another blue and black wire for speed/rpm sensor, resistance measured at 2k setting is 0.250 ohm. There is one more orange wire proabably for clutch that i am not sure but it measures no resistance looks like open circuit.

 

my thought was belt but possible tensioner but could also be the clutch itself.
idk if a the AC light will flash is the computer prevents the AC from engaging due to lack of gas, incorrect pressures, or some other fault.
im not an expert or even all that knowledgeable with hvac but, does a flashing AC light only mean mismatched speeds?

 

I am ordering a new ac compressor and will replace it. Just cannot figured it out how could all the components failed at same time ? Like rpm sensor, flow sensor, clutch ..

 

did everything fail?

 

Looks like from the resistance value of all the components that everything fails all together.

 

My ac compressor started working again by itself and was working good for some days. My compressor works like when it feels, today i am in good mood.🤪

 

i think its unlikely that everything failed all at once like that.
and the fact that it just started working proves that. once there is a short in a circuit, it will not "fix itself".

full disclosure, my knowledge with HVAC is not all there. so i could be wrong but to me, it sounds like there is/was one sensor that either did its job or was malfunctioning and preventing power from going to everything else.

either way, its "cool" that it started working again lol. good luck and hopefully it keeps on workin'.

 

I ordered a new compressor and measured the resistance with that, every value was exactly same except open circuit in magnetic clutch. I replaced the compressor and ac started working perfect.