99 international 9900 a/c problem

High pressure cut off switch?

 

Replace comp. with new not rebuilt, before it blows up and fills system with scraps of steel.

 

Maybe its not building to much pressure maybe that blow off valve is bad releasing at a lower pressure than it should

 

If I remember correctly, somewhere around 2.75 lbs. You should have a sight glass on your receiver drier for that system. When engine fan is off, charge it until sight glass clears and stop charging immediately, when fan kicks on, within a few seconds you should see bubbles pass through sight glass and then clear back up quickly.

 

? Is the new comp. cuting off then back on again after it starts blowing cold? AT idle it should cut off and cycle to keep it from iceing up an over pressure the system, themo. is inside heater box it is a 2 screw replacement, If your truck has a rear sleeper a/c blower box it will take a little more than 3lbs waching sight glass for the bubbles to stop will give you the sign to stop filling

 

I'm not here to argue with you, but I think that year model has the lower profile hvac box and uses a low pressure ccot switch on the underside of it to cycle compressor from freeze up. I could be wrong, no doubt.

 

Sounds like the engine fan is not coming, and you have an APADS module. On systems without an APADS you have both a fan pressure switch to turn on the fan, and a high pressure cutout. I doubt both switches are bad. With an APADS module, there is only one switch which may be stuck. Either way, your compressor is being left on when high side pressures are too high.