[surfahjammer]

Howzit all. I have a 2001 Frontier Crew Cab with a V-6 5spd. Recently my ac has been going on and off. When the compressors on it's ice cold. But the compressors been going off and on too much lately. The system does'nt have a leak because when it's on I checked the psi and it reads about 50psi. Someone told me there's a sensor called a thermo amplifier that controls the compressor. It's located behind the glove box. Apparently it's known to go bad on the Frontier and Xterra models often. I'm thinking of changing out this part. But before I do does anyone know if it's possible to "jump" the sensor to bypass it to see if the compressor stays on? Has anyone done it or have any ideas on it? I'd like to try and isolate this as being the problem before I spend any money on this issue.

 

[joefrontier2]

The part is about 35.00$, do not try and jumper the part. The thermal amp is there to save your compressor from freezing itself to death. Just change the part and you should be good.

 

[surfahjammer]

Hey Joe does it matter where in the box the thermo amplifier is set? I notice mines is towards the back of the box. Where did you set yours when you replaced it? Or can you just throw it into the box without setting it anywhere?

 

[joefrontier2]

lol - I threw it in the box.

I plan on redoing it this year sometime when I remember.

 

[surfahjammer]

Well, I installed my new thermal amp today and even set it near where the original was and my ac system is still doing the same thing. When i'm idling or driving at low speeds it's usually ice cold. But when i'm going 40+ mph it goes back to regular air temperature. I'm going to check the psi again in the system to see if i'm still in the good range. I think I am though because it does get ice cold at times. I think the compressor is still shutting off too much. Any ideas.

 

[joefrontier2]

Do you have in cabin air filters in the box? This would be to the right of where you put the thermal amp in?

If your pressure is good then it could possibly be your compressor. However, I don't it's the compressor if you pulling cold air sitting still.

 

[surfahjammer]

Yea I don't think anything's wrong with the compressor. Because when it does switch on it pumps out ice cold air. The problem has to do with why the compressor shuts off too long. And I did'nt notice any air filters. I don't see how that can cause the compressor to go off. Where exactly is it suppose to be anyway?

 

[joefrontier2]

Ok to the right side of where you stuck the thermal protector there is a verticle slot that are for air filters. The slot should be about an inch wide and run form the top of the box to the bottom. Reason I ask is that air flow could be cut down if there is a lot debris clogged in the filters and should be cleaned anyhow.

If you go further right you will see a round housing which is the in cabin fan. The fan blows air across the condenser and the filters block debris clogging the condenser.

You may not have the filters and I've heard some were not cut into the box and was suppose to me a dealer setup item.

Just FYI - I luckily had the filters as there was nesting material in my box.

I'd take a look if you can to see if the front of the condenser is clear of debris. In the meantime I will see if I can come up with why it would your compressor would be kicking off.

 

[surfahjammer]

What a surprise! I checked my psi while the compressor was running and it read 65psi and ice cold. Which is in the red zone and overcharged. Could this be why the compressor shuts off too much? Anyway, I discharged it down to 55psi and ran it for 5 minutes just idling while parked and it stayed ice cold. Tomorrow will be the test though when I run it while driving. If it stays cold while driving then i'll know. I guess I overcharged it before I changed out the thermal amp. Thinking it just needed a recharge. Before all this happened the ac system was problem free for years. Then the compressor started acting erratic and it was off and on coldness. Maybe the thermal amp was bad and now it's the overcharge that's causing the problem. I'll find out tomorrow. The fan blows strong so I don't think air filters are an issue here. Thanks all for your input. Stay tuned.

 

[surfahjammer]

Hey all. I ran the ac while driving and here's how it breaksdown. While idling and up to speeds of about 35 mph the ac stays ice cold. But at speeds above 35mph it loses its chill. Anybody have any ideas?

 

[surfahjammer]

What else could cause the ac compressor to shut off too much?

 

[wiyr]

What else could cause the ac compressor to shut off too much?

Maybe the clutch is going bad and slips at high speed? or the belt is loose?

 

[surfahjammer]

Thanks wiyr. Sounds probable. Do you know how can I check if the clutch is going bad and if the belt is loose? Anybody? What are typical signs that these parts are going bad or need adjusting?