Hi there, I have a 1996 honda accord ex coupe. About a week ago my a/c was working perfectly when I was running some errands. When I came back out to my car and started it up again, the a/c didn't work anymore. The compressor does not engage nor do the fans turn on. The vent fan works normally, but the cooling capability was suddenly nonexistant. I have done some trouble shooting. First, I ran a jumper wire to the compressor and got that to work. Checked the connectors for the relays and found I have power. Found one bad relay, replaced that, and still no change. I checked the refrigerant levels on the low side, those were normal. I tested the pressure switch conector and have power there. I ran a jumper wire from the pressure switch to a ground. The compressor engages and fans come on. I tried putting new 134a in and the pressure wouldnt stay. So, i put some sure seal and then put again yet more 134a into the system. while putting the new can of 134a in i had to jump the pressure switch to get the 134a in the system. While the pressure switch is jumped i get cool air the temperture is in the the 30s. But, when i returned the plug back to the switch the compressor will not engauge. when i jump it again it comes on and cool air kicks in. Could anyone help me i had a previous post https://honda-tech.com/forums/showth...4#post43213714

 

Recover and Evacuate the system. Put some R134a compatible UV dye in the system and recharge to the factory recomended weight of R134a. The system should operate. After a couple of days you should be able to identify the leak using some UV glasses and a UV light.

That vintage Accord does not have cabin air filters. This allows pine needles, leaves and other acidic debris to enter the evaperator unit. After enough time, corrosion will create a leak in the evaperator. I suspect if you have a leak it will be there. That is of course unless it isn't somewhere else!

 

You need to buy/rent an a/c manifold gauge set. This will tell you high and low side pressure in the system as well as allow you to recharge properly.

DO NOT KEEP ADDING REFRIGERANT!!!

You can overcharge the system, at the very least it will be dumped into the atmosphere through the compressors relief valve. At the worst you will blow up the compressor. Same as if you jumper the switch to kick the air on

It sounds to me like you have a bad a/c pressure cutout switch. This interrupts the air conditioning switch circuit when the pressure drops below 28 PSI or above 455 PSI to keep the compressor from being damaged due to system failure. If your low side pressure is above 28 PSI or below 455 then you have a bad pressure switch. Have the system recovered professionally, replace the switch, then evacuate and recharge to system capacity. (600-650 grams/21.1-22.9 oz R-134a)

https://honda-tech.com/forums/honda-accord-1990-2002-2/how-evacuate-recharge-your-r134a-c-system-2818297/

 

Yup, replace that pressure switch. Evan the system when you recharge or you will likely never be happy with the temperature of the air.

 

System dynamic pressures change based on various environmental conditions. The recommended way to charge a system is by weight.