New guy with an AC question

[96SLE]

So,what your saying is I should jumper from the dryer to the compressor or rear of compressor to front of compressor right?

 

[SunlitComet]

No just disconnect one sensor connector at a time and jumper the two wires in them. while the other connectors are still attached.

 

[99whitehoe]

Like was already said sounds to me like your low pressure switch is open causing you to get no voltage to the compressor switch located behind the compressor clutch. Just because you have pressure on your gauge does not mean that your system is full of refrigerant. If you jump out your low pressure switch and the compressor comes on I wonder what your pressure would be. I would think that if your compressor still does not come on once you jump the low pressure switch then your compressor clutch or compressor itself is locked up. Just my .02

 

[96SLE]

Thanks alot for all the advice.It looks like I'm getting somewhere now.When I put the jumper in the connector on the dryer the compressor kicks in with no funny noises.I let it cycle on and off about ten times and then put a can of freon in while I left it running.The line going straight back towards the firewall gets a little cooler and I think I was getting a little cooler air in the truck.I guess if I get more freon I will be in business.

 

[SunlitComet]

that is supposed to be the cycling switch. After you fed some refrigerant into it were you able to reconnect it and it would would on it own? remember only to open the freon valve when compressor is engaged so the freon does not have to fight so much to get in the system. just don't over charge.

---------- Post added at 10:30 PM ---------- Previous post was at 10:29 PM ----------

One other thing if you get more refrigerant get some with a UV dye in it so you can get a UV light and find leaks in the darkness.

 

[96SLE]

OK,I added another can of refrigerant with dye today and the air blows pretty cool now.I dont know how accurate my guage is since its the cheapy that comes with the refrigerant from Walmart but when the compressor first kicks in it shows 35 psi and after running for about 10-15 seconds it drops to 25 psi and the compressor turns off.It stays off for about 5-10 seconds and comes back on.Does this sound right?I dont know how much refrigerant is needed but I have put about 27 ounces in so far.
Once again,thanks for all the help.The dealership quoted the previous owner $1000 to repair it and thanks to you guys I have less than $35 in it.

 

[gpracer1]

Yes you need more. The switch trips at about ~23 psi. If it is tripping at idle, then you need more freon because as soon as you drive/rev the low side will go even lower. You may be 1-2 full cans low still. Make sure you are doing this with the blowers on high.....that is important, otherwise the evap gets so cold the pressure drops and it cycles.
A normal system will cycle at idle if the blower is only on low.

 

[96SLE]

Yes,the blower is on high and it still trips at idle.I guess I'll get more refrigerant tomorrow.

 

[SunlitComet]

see if you can bump it up another 5 psi on the first number to ballpark it and be absolutely sure you valve cap is clean inside with no damage inside either and do not over-tighten it. Call your self good for now and keep an eye out for leaks. Always run your compressor for a about 10 minutes each week to keep the system in good shape.

---------- Post added at 06:47 PM ---------- Previous post was at 06:36 PM ----------

BTW your cycling rate is in a good area as well.

---------- Post added at 06:47 PM ---------- Previous post was at 06:47 PM ----------

you should get about 8 a minute while idling.

---------- Post added at 06:51 PM ---------- Previous post was at 06:47 PM ----------

If you are not cycling about that much when idling you charge may be getting low. If it stays on continuously not matter how hot it is, that will be the sign that it is time to go back in and find the leak

---------- Post added at 06:55 PM ---------- Previous post was at 06:51 PM ----------

Nuetral or drive running should not be an issue the rpm is bumped as needed by the PCM to always maintain a required 650 rpm minimum. Steering load, in gear, A/c on, lights doesn't matter.

 

[gpracer1]

see if you can bump it up another 5 psi on the first number to ballpark it and be absolutely sure you valve cap is clean inside with no damage inside either and do not over-tighten it. Call your self good for now and keep an eye out for leaks. Always run your compressor for a about 10 minutes each week to keep the system in good shape.

---------- Post added at 06:47 PM ---------- Previous post was at 06:36 PM ----------

BTW your cycling rate is in a good area as well.

---------- Post added at 06:47 PM ---------- Previous post was at 06:47 PM ----------

you should get about 8 a minute while idling.

---------- Post added at 06:51 PM ---------- Previous post was at 06:47 PM ----------

If you are not cycling about that much when idling you charge may be getting low. If it stays on continuously not matter how hot it is, that will be the sign that it is time to go back in and find the leak

I think you have that part backwards.
At idle if it is hot out and the system is charged correctly and on high blower.....it will never cycle. At idle the low side will be around ~32-45 psi depending on the ambient and in-truck ambient.
If you put the blower on low, then when the evap gets cold enough, the pressure will drop to 23 and it will start cycling.