Can someone tell me where is the low side and high side of the air conditioning of a 1990 Honda Accord EX? Is the low in the back and the high up front near the radiator? Also, does the coolant go only in the low side?

 

HP connection is on the drivers side near the radiator, and impossible to access w/o a 90 deg adapter. It is a non-standard (won't fit R12 hoses directly). LP connection is on the large LP hose in center of car (this is by memory as I no longer have my (90Ex) and will fit R12 hoses directly.

Coolant for diy should be installed only in low side. If you lost the coolant entirely, a vacuum pump is necessary before charging. It's much easier to get charge correct, by vacuuming to completely empty and charging by weight or cans of refrigerant. Charging should also use a manifold gauge set to know that pressures are reasonable.

W/ correct charge both lines to the evaporator (firewall on pax side) should be very cold.

good luck

 

Only the suction line( bigger line ) will feel cold if system works ok,, the smaller line ( discharge line ) will feel warm/hot .

 

If you feel the lines where they go into the firewall, both are cold since expansion valve is only inches away and cools high side also.

regards

 

I stand corrected. I checked on my 94EX and after 5 mins the high side was tepid to warm.

Sorry.

 

Checking a/c pipe temperature is a good diagnostic practice. You can get a pretty good indication of the pressures without even hooking up a gauge.