I need to put 134A refrigerant in my 2004 Grand

If it were mine, I'd want to be very sure what it was and so I always use a Repair Manual I can see and read, but that me.

may be low on 134a freon. The compressor cannot cycle without enough freon in the system. Buy a can at the store and add it to the system. if This does not work, have it serviced by a qualified a/c tech

For the 2000 Pontiac Grand Prix:
I do not know if you have the 3.1L V6 or the 3.8L (including Super Charger) V6; however I have included both below...

For the 3.1L V6:
Firing Order:
1-2-3-4-5-6
Cylinders:
......(back).......
'...1....3....5...'
____________
'...2....4....6...'
.......(front)
Ignition Coil Connections:
.'.5..2.'..'.3..6.'..'.4..1.'


For the 3.8L V6 including the Super Charger:
Firing Order:
1-6-5-4-3-2
Cylinders:
.....(back).......
'...2....4....6...'
____________
'...1....3....5...'
......(front)
Ignition Coil Connections:
(back)
o 6
o ---3
___
o 2
o ---5
___
o 4
o ---1
(front)

Let me know if this helped, or if you have additional information or questions. Feel Free to contact us at FixYa.com!

ok you have a voltage regulator sensor you need to take a voltmeter and check it if bad replace it it tells the alternator how much volts its recieving and how much to send out

A/C pressures when running? Low side 35-45 High side 225-275

being a 1993, it probably uses r-12 refrigerant which is baned by the epa and you probably have to be license to purchase it. best to get it serviced by a qualified tech. it is possible that the system is 134a, in which case the port will be a quick disconnect fitting on the low pressure side. the fitting for the low pressure is between the accumulator/dryer and the condenser. also the low pressure fitting is smaller the the high side. in either case if you have no experience, it's best to consult a set of instructions
http://www.aa1car.com/air_conditioning.htm

some generalmotors cars you had to use an adapter which you can get at most automotive stores like autozone you screw it on over the smaller unit and you leave it there then you can fill it

2004 PONTIAC GRAND PRIX GT 3.8L 231cid V6 FI (2) : Transmission-Automatic : Automatic Transmission Assembly

$1,688.79 Core deposit: $550.00 Total: $2,238.79

Under the hood, on passenger side. there are two caps one large one small, they are not close to each other. Use the small one. You will need fill kit. Follow the directions. Dont over fill system you will blow o-rings.

First you should check the refrigerant level and charge if needed.