I had an AC problem diagnosed by a professional firm and they determined my compressor is bad. Long story short.... I replaced the compressor, accumulator, and both front and rear expansion valves (2001 Montanna with front and rear air). I pumped vacuum for an hour, then filled with 2 lbs of R134a freon (spec is for 2.2 lbs.) Low side pressure at idle is 50 psi..... at 2000 rpm will drop to 40-45 psi. But high side stays constant around 200-250 psi. And air is only moderately cool coming out of vents.
Is it possible I purchased a bad compressor? It was a reman. I don't know what else it could be. I feel I have replaced everything that is reasonable.
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Re: AC problem with 2001 Montana passenger van
Did you replace the expansion valve?
Also try adding just a little more freon and see if that makes a difference....is there a sight glass you can view with the system activated to be sure you have it completely air free?
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An AC system blowing hot air is usually due to a low freon charge or a non operational AC compressor. If the fuse blows, disconnect the compressor electrical plug and turn on the AC. If the fuse doesn't blow, suspect a compressor problem. If the fuse continues to blow with the compressor disconnected, there is a direct short between the ON/OFF switch and the compressor which can take hours to diagnose
it looks like you may have a bad A/V control unit. this is a very expensive part and should be diagnosed by a professional before replacing. Things like power, ground, and communication lines will need to be checked with proper equipment to determine if it is bad. on a side note these are fairly common failures in nissans. occasionally they will cause the vehicle not to start as well.
buy a falcon... just kidding mate. it is probably and after market alarm yes???? hard to diagnose without knowing the brand, model and features or your alarm but long story short it is well worth the cost to get a professional to install a new one. the issues you are experiencing could be due to a rookie installing an alarm, a faulty sensor, bad earth, over sensitive shock/tilt sensor, shoddy constant....the list goes on. an alarm is worth doing it right.
Hi, no, they are not related. The oxygen sensor(s) are part of the ignition/emissions sytem and help regulate fuel flow/mixture. The A/C system is self contained and does not affect other engine systems. Mike
Could be either. Usually if the compressor is cycling than its usually low on refrigerant. Could be pressure sensor. Could be cooling fan. I would have a different tech look at it. It is hard to diagnose what is going on without knowing pressures of the high and low side from a gage hooked up to the system.
It could be that there was more than one leak and the dealer found only one. The AC system has two pressure switches to protect the compressor from damage---a low press. switch cuts off the compressor when there is not enough refrigerant in the system, the high switch cuts off when pressures get so high they could blow out the seals. Both are a result of a leak--refrigerant leaks out and air can leak in. Air will compress and when it does, it gets hot--so no cooling, and pressures go way up. So the compressor may have been stopped by those protective switches.
Of course, there could be a bad relay or other circuit malfunction.
Another possibility is that the compressor sat too long before being repaired (but we are talking about weeks going by here, not days). The air and moisture (humidity) that leaks into the system during this time creates acids that will attack the metal reed valves in the compressor. On restart, the damaged metal valves eat themselves in short order. If this is the case, the compressor ran until it seized and will need to be replaced. This particular problem is impossible to diagnose. So the dealer may have done his best.
It needs to be diagnosed. It's normal for the AC to shut down when the engine overheats. The engine computer (called the ECU - Engine Control Unit) monitors the coolant temperature by means of a coolant temperature sensor (cts). When this sensor tells the computer the engine is too hot (above 230 to 240 degrees), the ECU turns off the AC compressor and the cooling system fans go to MAXIMUM (HIGH) speed. By the way, there are two engine/coolant temp sensors - one for the instrument gauges, the other for the ECU. If this sensor is malfunctioning, it can cause the symptom you describe - BUT that needs to be verified. Best solution, take it back into the mechanics/technicians and have them determine if that's all this is, because if it isn't, something else could be seriously wrong (clogged radiator, malfunctioning water pump, bad thermostat (even though it's new (or maybe it didn't actually get replaced), and there's a slew of other possible causes.. leaking head gasket for one. Best have the professionals (if they are professional) diagnose it.
I had the same problem with the over temp sensor on the compressor. I had it repaired at the dealer for $200.00 plus. I just had the same problem reoccur. This time I bypassed the switch myself.
There is a small wire harness that runs from the compressor above the radiator, inside there are three wires. After determining which ones to jump " two smaller gage blue" the AC system works fine in all modes.