I have heating and A/C in my '96 Chevy Silverado. But I noticed lately that only the windshield vent and the lower vents for the feet are blowing air. When I turn on the A/C, there is a loud squeal for about 3 or 4 seconds, then a mighty blast of air--except for the vents aimed at the upper body. Could this piping be clogged? How to clean it out? Note this is farm truck so it sits a lot and critters might have crawled around and nested. No sign from the outside.
replace vacuum lines and ac clutch
The answer is....stopped by gas station tonight. Opened the hood, checking the transmission fluid while running, then checked oil etc. Then thought about the air cleaner. Opened up its big ole box and took the filter out. Then I noticed...bits of cloth down one vent. Mouse nest. Cleaned out most with a piece of hooked copper wire, then used a nearby vacuum there to suck it clean. Could tell from the nest materials where the mice had gotten it at the farm.
Thanks for reporting back with the fix.
Ok glad that solved your problem, though I don't understand how. Even if your air cleaner had been completely clogged, the engine would run poorly, but you would still have plenty of vacuum to operate the HVAC system. Anyway, with all that garbage you had in there, you should replace the air cleaner element. I also don't see what it has to do with the squealing. This is your engine air cleaner you're talking about right? I don't think '96 pickups had cabin air filters.
You are correct: The 96 does not have a cabin air filter. I think some people mistake the AC evaporator for that. I also took out the glove box and the blower, and vacuumed that area out--also full o f debris and the start of another mouse nest
Since your handle says farmer. Have you checked the cabin air filter? It may be full of bean dust.
