I just purchased a 2000 Frontier with the 4 cylinder engine. The dealer replaced the evaporator coil and recharged the system. Yesterday, I drove the truck about 40 minutes and the A/C worked great. After restarting the truck after the 40 minute run, the A/C was blowing warm air?!? I shut the engine off, then restarted and it was still blowing warm air. This morning, I started the engine and the A/C works great (what the...).
Any suggestions on where to start with the diagnosis of the A/C system?
Hey, Jeff. You need to have your freon level checked. The high side pressure shoud read about 225 to 275 psi and the low side pressure should read about 35 to 50 psi. If they just replaced the evaporator core in the truck, sounds like they had a leak and knew about it. The evaporator may not have been your leak. If the system is low, the leak is somewhere else.
If you have your freon level checked and it is o.k., you may have a problem in the duct work. The first thing I would check is the temp. control cable in the dash. If you pull the cover off of the dash around the control panel and losen the screws holding the a.c. control panel on you can see behind it on the passenger side. The cable is held in place with a small metal clip that attaches to the cable housing and snaps into the bottom of the control panel. I have seen the metal clip pop out of place causing the cable to move freely, thus preventing your hot/cold duct from opening and closing properly.
I had some one service my 02. Same issues as yours but i had a v6. It was a bad hose. They OVERSERVICED IT causing the high pressure switch to turn off the compressor.
I removed some freon and now its a happy camper. I used one of those over the counter charging kits gauge. Its like $30 for the can with freon and it has a gauge on it. Mine read in the red so i knew it was over charged.
Hey, Jeff. You need to have your freon level checked. The high side pressure shoud read about 225 to 275 psi and the low side pressure should read about 35 to 50 psi.
killen702:
Started truck and turned on the A/C. Compressor did not run. Readings:
High side: 100psi
Low sie: 34 psi
I then took truck on a test drive...I "punched into it" and A/C blew cold air! Checked gauges again. Readings:
High side: 110 psi
Low side: 35 psi
I noticed that the system has leak detector in it but did not notice any leaks. Temp. cable in the a/c control is connected.
I'm thinking about driving it through the used car department window where I bought it. They "could not duplicate" condition last week. They elaborated and stated that the evap and expansion valve were changed; not the dryer?!? I thought that was SOP? What needs to be done next?
Your pressures are too low. the high side and low side should even out if the compressor is not running. I would try adding some freon to the system. You can pick up r134a at auto zone, advance, or wal mart and put it in yourself. If you have a gauge set you need to ad one can at a time but no more than two cans total. You don't want to overfill the system. After doing that you should end up with pressures like 250/45 or so. If you lived close to Killen, Al. I would just tell you to run it by my house and we could figure it out. Good luck.
After 2 weeks, the dealer finally fixed the evaporator connector o rings. Msubullyfan was right. They pinched the o rings and it was visibly leaking at the connections. That solved the leak but didn't solve the overall problem. Intermittantly, the compressor cycles off and won't come back on...until it wants to. I believe it is possessed!
Does this sound like a pressure switch problem and if so, which one and how much $$$ if I change it myself?
i think your head pressure is too high, i over charged mine one time and the compressor would run about 10sec and cut off and then on again, i got it check by a friend and he let the head pressure to about 350psi and i blews cold as ice,
my friend said that the new r13 builds a lot more pressure under heat temperatures
he also said that during the hottest part of the summer u have to let some freon out and in the fall u might have to said some
make u wonder way they changed over for r12 to r13
Try going to a Nissan parts department and asking if your truck has a Thermo Control Amp. It is a small sensor that directly mounts onto the evaporator coil and also controls the compressor. The symptoms you are describing sounds almost like your car has a bad thermo control amp. Don't forget to take your VIN number so they can check.
Linear Mode
