Where is the low pressure line AC for Express 1500

How much freon have you added? It is either still low on freon or the orfice tube is restricted. http://rechargeac.com/how-to/ac-system-pressure-chart

If you get a can of r134 with the end it should only fit the correct line to add freon.

it's straight below the high pressure valve about a foot. it's a little stem with a cap on it. it's kind of by the oil flter. i didn't see it the first time i looked either.

check all fuses first. does ac compressor come on? if not, unplug pressure switch in low pressure line near where you add freon and short across pigtail. comes on now and cools? replace switch. if not plug back in. apply manual voltage to ac compressor. comes on and cools? if not compressor or clutch is bad. if it does, check ac relay. that's about all you can do with limited tools in the driveway. if no progress has been made, time to take it to the pros.

You have to locate the low pressure line and connector port. Trace the two lines back to the firewall that come from the compressor. You will find 1 port on each line. They are usually covered by a plastic cap of some type that unscrews. Your refill hose, assuming you have a standard refill can with attached gauge, will only attached to the low pressure side. The two ports are slightly different in size. The low pressure side should be the larger of the two lines you are tracing from the compressor.

Check the low pressure switch,it is on the dryer or on the low side line,the large ac line,this can be the problem,try jumping the two wires that are plugged into the switch.If the freon is low,or out,this switch will not allow the ac compressor to come on.

Follow the large line from the firewall it is the low pressure line,it will have the service port on it.Use the one hose kit from the auto parts store and apply the freon can on one end,and clip on the other end on the service port,then start the engine turn the ac on high bloewer motor,and max air,or recirculation,

The ac system may need freon added,if the system is low,or out of freon,it will not allow the ac compressor to come on.

passengers side under the hood.....by the firewall.....

add freon to low pressure side . low pressure side is large line with small fitting. high pressure line has a large fitting.