Freon leaking at the fill valve. Compressor will not come on.

Make sure the compressor is turning - check out the compressor clutch for operation. Also check the operation of the thermostat which turns on/off the clutch.

Sure the freon is in there? If you have a nasty leak it will come out as fast as you put it in. Also check the low pressure shut off valve. If stuck in the open position the clutch will not activate the compressor.

no you do not need a new compressor; take your car to an ac shop and, make sure they change the fill valves (they look like oversized tire valves inside the compressor where the freon lines attach (after time the o-rings fail in these and, they leak refrigerant; obviously your dealer has an incompetent ac mechanic or. these should have been inspected and, if having failed: replaced.

line that goes to compressor is low side line out of compressor is high side
always fill on low side
also r12 hase been band for sevral years and should not be used
if this freon is r-12 conpatible or replacment then your fine
after leak been repaired and system pressurized and vacumed out
start engine put a/c to max blower motor to hi open windows
conect your fill bottle to low side open valve and system will start filling
when freon reach enougt pressure the compressor should start and draw in
the freon if it fails to start you could jump the low pressure swich to help draw in
freon when system has drawned its capacity shut off your bottle and disconect your line to fill
cap off the valve
if compressor fail to start you have another issus could be electrical
take CAUTION doing repairs to a/c system

Normally due to low freon. Also, notice if the a/c compressor clutch engages, as it will not if the freon is low.

Grand Am has an expansion valve. Link below has part number and picture of what you are looking for.
http://www.discountacparts.com/addtocart~year~1998~make~Pontiac~model~Grand_AM~descript~A-C_Compressor~part~60-40281.asp

Unfortunately, I do not know precisely. But for the most part auto a/c's are all the same. Below I will describe how to find it. I have also included a aguide to determine system operability that may or may not be helpful. Just trace the system with flow path described below the valve has to be between condensor and evaporator.

Reminder the flow for the a/c system is :
1. From the compressor a high pressure (HP) gas goes to the condenser in front of the radiator.
2. From the condenser a HP liquid goes to an expansion device (orifice tube or expansion valve)
3. From expansion device the low pressure gas enters the firewall to the evaporator.
4. From evaporator the low pressure liquid/gas mixture goes through the dryer back to the compressor suction.

Below is a guide to troubleshoot and check system function. This can be done by most folks.

Look at the front of the ac compressor and have someone turn on the ac from inside the car. The front of the pulley(clutch) will spin when turned on.

If it does not spin, the low pressure switch (LPS) is not satisfied. Meaning there is not enough freon in the system to operate the system. Means low freon capicity because of a leak.

The LPS can be jumpered to cause the compressor to run (clutch to engaged) which will draw the freon in the system.

The LPS is usually a two wire sensor on the suction of the compressor. (between evaporator and compressor) Unplug the sensor and install a jumper, this will engage the clutch. Connect a new can of freon
and fill to system capacity.

The capacity of the ac system will be on a label under the hood, do not overfill. Probably about 2 lbs. Local parts stores (Auto Zone and Advance) will have freon with stop leak. This may help the leak. They also make a freon with a UV dye. I always add a single can with dye so that if stop leak does not work I can find the leak in the future.

The system should be filled until suction pressure is about 30 to 38 psi..

Below is a guide to troubleshoot and check system function. This can be done by most folks.

Look at the front of the ac compressor and have someone turn on the ac from inside the car. The front of the pulley(clutch) will spin when turned on.

If it does not spin, the low pressure switch (LPS) is not satisfied. Meaning there is not enough freon in the system to operate the system. Means low freon capicity because of a leak.

The LPS can be jumpered to cause the compressor to run (clutch to engaged) which will draw the freon in the system.

The LPS is usually a two wire sensor on the suction of the compressor. (between evaporator and compressor) Unplug the sensor and install a jumper, this will engage the clutch. Connect a new can of freon
and fill to system capacity.

The capacity of the ac system will be on a label under the hood, do not overfill. Probably about 2 lbs. Local parts stores (Auto Zone and Advance) will have freon with stop leak. This may help the leak. They also make a freon with a UV dye. I always add a single can with dye so that if stop leak does not work I can find the leak in the future.

The system should be filled until suction pressure is about 30 to 38 psi..

Remember the flow for the a/c system is :
1. From the compressor a high pressure (HP) gas goes to the condenser in front of the radiator.
2. From the condenser a HP liquid goes to an expansion device (orifice tube or expansion valve)
3. From expansion device the low pressure gas enters the firewall to the evaporator.
4. From evaporator the low pressure liquid/gas mixture goes through the dryer back to the compressor suction.

Below is a guide to troubleshoot and check system function. This can be done by most folks.

Look at the front of the ac compressor and have someone turn on the ac from inside the car. The front of the pulley(clutch) will spin when turned on.

If it does not spin, the low pressure switch (LPS) is not satisfied. Meaning there is not enough freon in the system to operate the system. Means low freon capicity because of a leak.

The LPS can be jumpered to cause the compressor to run (clutch to engaged) which will draw the freon in the system.

The LPS is usually a two wire sensor on the suction of the compressor. (between evaporator and compressor) Unplug the sensor and install a jumper, this will engage the clutch. Connect a new can of freon
and fill to system capacity.

The capacity of the ac system will be on a label under the hood, do not overfill. Probably about 2 lbs. Local parts stores (Auto Zone and Advance) will have freon with stop leak. This may help the leak. They also make a freon with a UV dye. I always add a single can with dye so that if stop leak does not work I can find the leak in the future.

The system should be filled until suction pressure is about 30 to 38 psi..

Remember the flow for the a/c system is :
1. From the compressor a high pressure (HP) gas goes to the condenser in front of the radiator.
2. From the condenser a HP liquid goes to an expansion device (orifice tube or expansion valve)
3. From expansion device the low pressure gas enters the firewall to the evaporator.
4. From evaporator the low pressure liquid/gas mixture goes through the dryer back to the compressor suction.

Below is a guide to troubleshoot and check system function. This can be done by most folks.

Look at the front of the ac compressor and have someone turn on the ac from inside the car. The front of the pulley(clutch) will spin when turned on.

If it does not spin, the low pressure switch (LPS) is not satisfied. Meaning there is not enough freon in the system to operate the system. Means low freon capicity because of a leak.

The LPS can be jumpered to cause the compressor to run (clutch to engaged) which will draw the freon in the system.

The LPS is usually a two wire sensor on the suction of the compressor. (between evaporator and compressor) Unplug the sensor and install a jumper, this will engage the clutch. Connect a new can of freon
and fill to system capacity.

The capacity of the ac system will be on a label under the hood, do not overfill. Probably about 2 lbs. Local parts stores (Auto Zone and Advance) will have freon with stop leak. This may help the leak. They also make a freon with a UV dye. I always add a single can with dye so that if stop leak does not work I can find the leak in the future.

The system should be filled until suction pressure is about 30 to 38 psi..

Remember the flow for the a/c system is :
1. From the compressor a high pressure (HP) gas goes to the condenser in front of the radiator.
2. From the condenser a HP liquid goes to an expansion device (orifice tube or expansion valve)
3. From expansion device the low pressure gas enters the firewall to the evaporator.
4. From evaporator the low pressure liquid/gas mixture goes through the dryer back to the compressor suction.

you just might be low on freon...have it checked at your local repair shop or you can even add it yourself just look for the fill valve on the (big) low pressure line from the compressor

2000 maxima is filled with R134, not freon. You don't need retro fit kit. Get couple of cans of R134 and pump it into the low side valve /small fiting, while A/C compressor is engaged. If your compressor is not coming on, jump the low side pressure switch to make the compressor come on and than the R134 will get sucked in to your system through the low side line. The proper way to do this is to put a/c system under vaccum for 15 minutes at least and watch for leak/gauges coming/loosing vaccum. Than pump R134 into the HIGH side valve with engine OFF.