on my 98 Blazer been driving it without A/C for about a year and a half now and finally decided to mess with it a bit since I've been frying.. i found the original reason it quit working... just a stupid relay to the compresser clutch, replaced that and topped off the system with some cheap O'Riley's Coolant. the guage i have is reading correct for the low side (About 42 psi) and the compresser is kickin on and off but still blowing not cold air... its cooler than outside air so its doing something but still not working right.. any ideas where to go from here. School me on A/C...