If the system was low, then you have a leak. It will not heal. Two weeks ago in Phoenix is was less hot (can't say "cooler"). If system was truly 100% 2 weeks ago and went to bad, then there's a larger leak recently. I hope the can of R134a/UV dye that you added did NOT contain any sealer ...

I'm not an expert like GM Tech - unless living in Arizona heat qualifies one automatically - but I agree that it sounds quite low on refrigerant. Pressures and "Started the truck and the compressor would just turn itself on and off every few seconds" are HUGE clues. I agree: have a REAL AC...

HECAT wrote:Cabin air filter clogged?

Or blower wheel loose on blower motor shaft

Or evaporator leak mixing leaked oil and dust clogging the airflow, or leaves debris having gotten sucked up onto the evaporator

Or diverter "doors" diverting air under dash, or to windshield instead

I'd also keep with R-12. What went wrong, like why are condenser and evaporator needed, did a compressor seize and contaminate the system??

Tim wrote:I got nothing. Could not even find it in Mitchell.

Thanks for checking, and I checked my used parts boxes for him. I turned out that I had 3 spare AC relays, and 2 partial harnesses.

The guy I know was able to find such relay and full harness from a parts yard, so he didn't need mine.

If I was in that situation (don't know how many miles away shop is), I'd throw my bicycle in the back of the F-100, ride that home. And later ride that back and pick up the F-100. And I'm 63.

Well - and you know this already - leak testing a condenser is way easier than such for an evaporator, just because of access. Yes, I think UV dye can help pinpoint a condenser leak or maybe an evaporator leak (test the condensate drain) if you have UV light and goggles; maybe an electronic sniffer ...

Jag987 wrote:yup, a little leak is normal. I try to tighten them if they are leaking a little.... They all leak some, and yes the cap is the primary seal. Make sure the cap has a rubber seal in it.

Good caps are important part of the system.

Mr. Bill - this is off topic, but I saw your signature line "Experience is a hard teacher because she gives the test first, the lesson afterwards" -Vernon Law Well, Vernon Law rented a house a few up from my family in 1959 and 1960 on Gilmore Drive in Eastmont (an area east of the Pittsbur...

I charged the system with a 30lb tank so i relied on the pressure to know when it was full. The system take over 2lbs of r134a but the tank feels a good bit lighter and I think it may have been overcharged. Most experts on this site only recommend to charge by weight. If the system worked fine befo...