My maruti SX4 is 2yr old. The AC runs fine when the outside temperature is below 30 deg. But when its sunny and hot the blower starts to make thundering noise and also there is no cooling effect. First I thought there might be refrigerent leak but if that is the case there should be no cooling even when its not hot outside. Pls advice.

what sub model accord, v6 LX ,
manual or full climate control option??? guess full.
fuses not checked PCM scanned for DTC errors EVAC, hopeless/?
so car starts and runs sand drives ok, <<< not told that.
yes the AC brain on most modern cars is BCM brain controls
and the brain does control the AC compressor. if that is dead so be AC, THE COMPRESSOR CLUTCH, is run by PCM RELAY.
NOT TOLD OUTSIDE TEMPERATURE NOR COUNTRY../
HERE IS A LIST.
1: CHECK ALL FUSES FIRST, CAB AND ENGINE BAY ALL FUSE BOXES SKIP NONE.
2: CHECK IP CLUSTER FOR ERRORS ,ALARMS ERRORS OR LAMPS GLOWING OR IMMO LAMP SHOWS IMMO IS UNHAPPY, MODE.
3: ENGINE STARTS AND RUNS AND CAR DRIVES.?????????
4: HEAD LAMPS WORK KEY ON AND OFF. ,
5: OTHER ELECTRIC FAILURES OR JUST THE BLOWER ONLY?
6: SCAN THE pcM FOR ERRORS, AC IS CUT DEAD EVEN FOR ENGINE OVERHEATING OR OVERLOADED !!! OR IN LIMP MODE/
yah can't fix modern cars lacking a scan tool, no way./

bLOWER FACTS
PER THE SM BOOK REAL

THERE IS A BLOWER RELAY AND SOME FUSES. 12VDC SIDE.
FUSE 30 DASH
AND 21 HOOD, BOTH MUST BE GOOD. and fuse 12 V6
THE bLOWER gets GROUND FROM THIS
Audio-HVAC--Display Panel
l AND ITS BLOW POWER TRANSISTOR MODULE
SO WE KNOW THE TRANSISTOR IS off. IS CAUSE 1.
ONLY WHY REMAINS!!!!
YES THE CONTROLLER DOES NOT WANT TO RUN ANY DEAD BLOWER AND RISK ICE DAMAGE TO THE EVAP CORE.

THE Audio-HVAC Display Panel, READS MOTOR SPEED ACTUAL. speed (a kind blower tachometer wire)
IF SAY A INSECTS NEST JAMMED UP THE BLOWER FAN
THE AUDIO -HVAC, MODULE SEE THAT AND CUTS AC DEAD BY DESIGN AND HARD GOOD REASons/
the THE Audio-HVAC , has the ICE up sensor and monitors R134a
high/low switch and if wrong, tells the PCM to shut down its
Clutch solenoid to compressor ending all AC .
I am no sure what blower does.
but I can say this tell of blower works in heat mode or blower + no AC no HEAT mode. yes then the blower is not bad, nor the controller
what is wring is inputs to the controller are dead wrong
and not scanning the PCM after fuses is why you don't know.

l;earn now this works
Audio-HVAC
Display
Module
https://eautorepair.net/Marketing/Default.asp



not checking fuses first then scanning the PCm is why answers simple are not found.

like these and scads more.

Trouble Code: HVAC 12 (3.0L V6 VIN - Std)
A Problem in the Blower Motor Circuit

Trouble Code: HVAC 13 (3.0L V6 VIN - Std)
HVAC Control Unit Internal Error


Trouble Code: HVAC 14 (3.0L V6 VIN - Std)
An Open in the Evaporator Temperature Sensor Circuit (ICE Up preventions)

Trouble Code: HVAC 15 (3.0L V6 VIN - Std)
A Short in the Evaporator Temperature Sensor Circuit(ICE UP)

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If you're finding it difficult to service/repair your car, get one of those online manuals. You'll not have to wait for others to answer, or rely on mechanics and all. Plus i know a website that sells very cheap but very very good manuals online, without expiry i.e. for lifetime.

It all depends on the outside (ambient) air temperature. Your A/C low pressure switch is designed to turn the compressor off at 24 Psi. and turn it back on at 45 Psi. Most systems will normally run at between 25 and 40 Psi when the system is running on HIGH blower and "MAX" or "RECIRCULATE". A system that is fully charged may run at 25 Psi when the ambient temperature is 75 Deg. (F) and may run at 40 Psi when the ambient temperature is at 90 Deg. (F). (it can be even higher if ambient temperatures are higher than 90 Degrees.)

To properly diagnose a malfunctioning A/C system, the HIGH side pressure must also be checked. Restrictions in the system can make the low side pressure look normal while the high side pressure is high enough to blow hoses apart. (400+ Psi.)

make sure that the coils, ( the ac radiator ) are clean , blow them out with an air hose if you can get a hold of one, also, make sure the ac fan is coming on, it may start , but the sensor may be bad allowing it to turn off too soon , a normal rise in heat is expected when using the AC but if it is too hot you should feel the motor start to run rough, if its running fine, and the temp does move back to normal when the ac is turned off, and a qualified mechanic has checked it, your probably ok, you could have a sensitive gauge, , If the normal range of the gauge moves to hot and back during normal driving without the ac on, that would show the thermostat is also working

I have a 2000 pontiac grand prix with a digital climate control system. The heat quit working, it doesn't blow out any heat. Now that it is warm outside the air stopped blowing out any air. The digital temperature on the climate control is not correct. When it states that it is below 30 degrees on the ext and it is warm outside the air wont be cold. Once it starts going above 30 degrees the air gets colder. Today the blower stop working all together. Was told it maybe the climate control unit was bad. You can hear the door opening/shutting when you switch the temp from cold to hot. But there was no heat blowing out whatsoever in the winter time. Could you please give me your opinion on whether or not it is the climate control unit or something else?

replace temp. sensor

Are there any service engine soon lights on associated with this problem?

Possible CTS (Coolant Temperature Sensor) or another sensor giving faulty data for the cool air temperature.

Check spark and gas delivery when cool, below 70 deg. If the spark is not being delivered or the fuel injectors are not delivering fuel at this temperature, it will explain why it doesn't run right until it is warmed up.

When your engine thermostat has failed or is sticking open, the engine fluid isn't able to reach a temperature that lets your heater core get hot enough to produce worthwhile heat to blow into the passenger's compartment. It is also not good for your engine to run below design temperature.
If you have a dashboard temp gauge, if your thermostat is stuck open, that gauge will probably stay in the cold area.
I would think that that is the problem, and I would have the thermostat changed (not a very difficult or expensive job).
Hope this helps you.

There are 3 potential problems:
--faulty thermostat. If it is not opening all the way by the time the engine reaches 160-180 deg F...then coolant is not flowing enough.
--partially blocked radiator caused by build up of rust over the years if never flushed as regular maintenance.
--Insufficient coolant to water ratio. Should be at least 30% or more coolant in the radiator.
--Or combination of above.
Hope this helps.
WJ