'01 9400 AC issues

You have no gas!!!! Jumping an AC unit will always make it engage but it needs gas to engage itself and work. The gauges going in the opposite direction should have been a MAJOR clue.

I never said the shop put the hoses on backwards. If they removed your condenser to put the new radiator in they probably didn't recharge your system or they broke it causes a leak.

You need to have a vacuum put on the lines to see if it holds pressure and then recharge.

 

If the low side pressure drops to zero or slight vacuum and the high side is really high when you jump the compressor this is usually a stuck closed expansion valve.

 

I had a 9400, you jus lift the condenser out of the way to change the radiator, on mine a hose was bent and started a leak. I think you are overthinking this find a ac shop or non dealer truck repair, nothing money won't fix.

TA is last choice, take a cap off the the valve where they hooked the gauges and there is a valve just like a tire, press it with a screwdriver and see if ther is any freon at all. The gauges would move with compressed running because it is just a pump and will move the air in the system.

I know a top ac shop in OKC if your out this way.

 

Right on!

 

You can only cool the air so much. Usual rule of thumb is 20 degrees. So, if the inside air is 90 then the best it can do is 70. Once the air inside is 80 it will blow 60 and so on. If you measure the air before the evaporator then after you should see a 20 degree difference.

 

A really quick health check is simply feel the a/c return line, should be ice cold and your heater box should be making water like crazy. If it is, but the vent temps are warm, there is hot air leaking in somehow.

 

People will say there's is much colder but keep in mind that cold air sinks so the air intake from your cab will be a lot colder then at eye level. If your running your truck overnight the engine fan should stay on and only on med fan. With the fan on high you warm up the lines too much.