A/c And Heat Not Working Properly

[jkost1066]

Hello all!

I am new to the site and have just recently purchased a 1994 Lexus SC400 that had only 65K miles on it. First off I wanted to say that this car is awesome! The only problem that I am having with the car is that the A/C and heat do not seem to be working properly. They both blow fine; however, the A/C barely blows cold and the heat barely blows hot. I am familiar with engines in that I have done two engine swaps (Camry and Supra) but I am unfamiliar with the "HVAC" systems in cars. I have attempted to do some research but have come up empty handed. Does anyone know what commonalities are in the heating and air conditioning systems? Any help with this issue is greatly appreciated!

--JK

[davemc]

Hello,

I am also brand new to this site. I have a '95 SC400. Neither my heat nor air are working. I have heard conflicting ideas about this. One person told me that the Heater Control Valve affects the heat as well as the AC. Another told me that this is not true and that it only controls the heat. That being said, when I purchased the vehicle, the heater control valve had been bypassed with a piece of conduit. A friend of mine recommended that use a HCV from another vehicle to save money. So, I put in at HCV that fit and my heat stopped working. I don't know about the AC, because it was winter and I didn't try it. So my questions are:

1) Does the HCV have anything to do at all with the AC?

2) Do I need to purchase the correct HCV to get my heat to work again?

Thank you!

[Essam]

Hello,

I am also brand new to this site. I have a '95 SC400. Neither my heat nor air are working. I have heard conflicting ideas about this. One person told me that the Heater Control Valve affects the heat as well as the AC. Another told me that this is not true and that it only controls the heat. That being said, when I purchased the vehicle, the heater control valve had been bypassed with a piece of conduit. A friend of mine recommended that use a HCV from another vehicle to save money. So, I put in at HCV that fit and my heat stopped working. I don't know about the AC, because it was winter and I didn't try it. So my questions are:

1) Does the HCV have anything to do at all with the AC?

2) Do I need to purchase the correct HCV to get my heat to work again?

Thank you!

Also, I have a 2003 GS 300. Sometimes the A/C will work other times it will not. It is fully charged with refrigerant. The mechanic said that the Expansion valve is bad and it ill take 8 hours labor to replace.