Like lowblack said, check your compressor. Soak the whole thing in soapy water. If I where you I wouldn't put any more dye in there. Nitrogen is good idea as well, you can put several hundred pounds in the system. If you still cant hear it My guess would be is the leak is in the evap coil or connections under the dash

 

I agree, if you are not seeing any signs of a leak then check the evaporator. You will probably see it stained with oil or dusty oil.

 

Hmm I didn't check the front of the compressor. It could be that, because it was working before I had to tear into the engine and the truck was down for a month. I had my feet all down there and may have kicked it a few times.

And yes I used the blue light with the yellow glasses in a dark room. It's pretty cool, but I only found minor splatter from when I originally injected the dye.

I'll check the front of the compressor and let you guys know what I find out.

 

Sometimes you can pull out the blower motor resistor and see the evaporator core. I found a leaking evap on a tahoe just the other day that way.

 

Where is the blower motor resistor? How do I access it?

 

Passenger side under the dash. There is a black plastic cover that runs under the dash from about the middle of the dash all the way to the kick panel on the passenger side. You need to remove that. It has about three or four 7mm (9/32) screws. A couple of the screws are a little hard to get to. Once the cover is off find the blower motor. It's near the passenger side kick panel. Follow the wires coming off of the blower motor to the blower motor resistor. Unplug the wires from the blower motor and the plug on the resistor. Two 5mm screws take the resistor out. You will probably need to use the uv light to see a leak there. Do your best to look at as much of the evap core that you can. The one I found Had a very small spot of dye up in the top corner. Good luck.

 

I looked for a leak for 4 weeks... kept messing withit when i had time.. And of course it was the Evap Core. $117 and get it charged back with 2#s of R134a for our 2000s.

Have fun buddy!!
I changed my Heater core last year so half the bolts were missing and most of the stuff was already broken... Easy fix.

 

For the record, it turned out to be the evaporator core!

 

mine was solid green.. what did yours look like?

I forgot to hook up 2 connections so my heater nor Defrost/Floor didn't work.. just A/C through the vents...

easy fix.

 

It was sort of brown/gold looking. The new one was perfectly silver