Hi all

Background: I purchased a salvaged 1999 Accord EX manual 4 cyl. When I purchased the car it did not have a condenser only a radiator and the single radiator fan. I am not sure but I believe the radiator was probable damaged in the crash along with the condenser but the guy I bought the car off only bothered to install a new radiator.

Anyway I am in the process of trying to fix the AC system. I purchased a new condenser and condenser fan and had my mechanic install them along with charging the system. However when the AC system is turned on the compressor clutch does not engage. I have checked the fuses and relays and clutch and confirmed that everything there is working (and it is) so I am led to believe that the car computer is not telling the compressor to turn on.

From the bit of research I have done it seems there are certain requirements to be met before the computer will turn on the compressor - pressure, temperatures, throttle position etc. I have found what appears to be a smashed sensor connector (but no sign of any sensor or what it connects to) very close to the radiator - on the same loom as the two horn connectors. I believe the (2) wires are yellow w/ silver strips and grey w/ red strips. I am thinking maybe this was a sensor for the radiator or condenser perhaps that is required to turn the compressor on? But I am not sure what this possible sensor is or where it is supposed to go. I know that wires are not for the bonnet alam sensor as the alarm comes on if I open the bonnet without disarming the alarm. Unless its for something stupid like license plate lights..

The heating/cooling system and dash panel works fine only doesn't cool very well without AC obviously, when I push the AC button on the dash the button lights up but the radiator and condenser fans do not come on when I do so (I read that they are supposed to apparently, along with the compressor). Both fans do come on however once the car gets hot. One strange thing I have noticed is that sometimes the two fans will come on when the engine temperature gauge is around midway and maintain the engine at that temperature, and other times they don't come on unless the engine temp gauge gets right up to the red zone, in which case the engine temp gets brought down and the fans don't come on again until it reaches the red zone again.

The engine warning light does not come on again once the engine is started.

Any help / feedback for my problem greatly appreciated.

 

There is a hi/lo pressure protection switch on the lower, pax side condensor fitting that should have two wires. I see blu/red and blu colors for wires in my manual. This switch would be in an area prone to damage in an accident. If this switch is disconnected, the AC will not work.

good luck

 

Thanks for that. I was able to confirm that the two wires are for the high/low pressure protection swith as you said - one of the line voltages was reading 5V to ground. Connecting the two wires together to similate the sensor activated the compressor clutch and turned on the radiator and condensor fans.

Now I just have to buy a sensor and find out where exactly it was supposed to go.. The condensor is not an original honda part but the pressure piping is. I can't find a blocking plug on the condensor or the high pressure piping / connector where the sensor is supposed to go.. Guess I'll have to go to the dealer and try and get the A/C shematics

 

You will have to discharge the system to install the switch in any case. I would suggest finding an OEM used condensor to place the switch near the wires. You should be able to find a good part for < $50 easy. Check car-part.com for a part near your zip code, go by to inspect/purchase.

good luck