Question about 1999 Dodge Ram

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Ac pump turns on and off constantly. checked pressure of system and ok pressure when pump is off then loss of pressure when on. no cold air at all.

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That is a low refrigerant sign you need to charge the system.. the compressor shuts off because the low preasure shutdown switch is triggerd when the compressor starts to move the refrigerant to the high side and shuts off thats why the preasure drops when the compressor clutch engages...

hope this helps.

Posted on Aug 01, 2009

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Hello everyone I have a 2004 nissan titan and when I am travelling down the highway the ac blows warm I have checked the freon level and it has the proper amount of refrigerent in it and the clutch fan...

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I have a 1999 Chevy Silverado, the a/c works fine for a while then blows hot. If I turn a/c off for a while, it will cool again, but after a little while, will blow hot. What could it be?

ok sounds like you may need to add a can or two of 134a freon which isnt too expensive you will have to have special gauges to make sure of the correct amount of refridgerent if you over fill the system you could bust a line on your condensor or worse screw up your ac pump but you can find 134a at all your local auto parts stores when you put the freon in you want the vehicle to run and the ac on high all the way cold and when the can is punctured shake it constantly until empty one way to cheat without using gauges is to hold you hand on the low pressure line when it gets cold that means you almost got it done make sure you do not connect the can to the high pressure side because you can blow up the can in your hand i would start with one little can then go check to see if you have cold air if its not frezzing cold you can put another one in until you are satisfied if you need anymore help just ask :)

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sounds like the system is either low or out of refrigerant. There is a low pressure switch in the system to shut it down in the event of freon loss. First , verify , then test for a freon leak. Once repaired, and recharged, will blow cold air again.

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Please help me with my air conditioning for my 1995 jetta

HI, giving the compressor 12v directly is not the way to go as you are bypassing the entire fail safe cercuit. it seem to me that your ac gas is low(can be checked via ac pressure gauges) wich means you have a system leak sumwhere. as soon as your hi/low pressure switch(depending on system) detect inferior pressure to the spesified pressure ,the ac compressor voltage is cut in order to protect the pump from seizure.

Or perhaps your evaporator(small radiator like unit behind dash) can get freezed up caused by either too mutch system gas(check pressure) or poor opperation of the expantion valve. the evaporator then has a sensor(themometer) wich measures evap. temp and if the value drops below spec (usially round about7degrees) the ac compressor will be cut once again(fail safe)

Maybe your ac compressor overheats due to inferior system oil/oil capasity, also note that only some systems incorperate the function of measuring ac pump temp. then again temp to high= fail safe=no12v to ac pump.

Good luck.

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