The directions on the Refrigerant can read, 'Install on the LOW pressure side only'.
Where is this coupler?

Thanks.

IF you went out and got an ac kit from autozone or anywhere like that, the kit should be dummy proof, just tap into the ac line nossle If i remember correctly, then the low preasure side on a car should be after the accumulator drier. And make sure the car is running while you do this, if not you can ruin your ac compressor.

If I remember correctly.....Low pressure is the valve right next to the battery.....Closest to the radiator. That'* the valve I used last summer when I recharged my A/C.

My 98 is the opposite, hi side is closest to the battery/radiator, low side further towards the firewall. I just had to replace the AC hose assy last week.

The low pressure will also be the larger of the two with fittings.

No your wrong, the one closest to the battery is the high side. The low side is closest to the reciever drier, strut tower.

Sellncars

The larger of the two lines is always the low side.

Yup, the low side on my old 1992 SE, 1994 SLE, 1999 SSEi, and current 1990 SSE is right on the reservoir near the powersteering pump and firewall on the passenger side.

I believe the dummy proofing is in the size of the valve where you hook up. It should only hook up to one of them.