Ok, so I just picked up a 97 RCSB C1500 and the blower motor works on all speeds just fine, however the air blowing out of the vents is very little for the speed I select. It's like there's a restriction somewhere. Can someone tell me an easy way to clean out the air vents? Would there be a bunch of **** built up on the ac evap? If so, what's the easiest way to access it? If I have to, I'll drill a 2 inch hole on the side or the bottom of the dash, vacuum it out and put a rubber plug in. Someone has to know of an easy way for me to do this

 

dang. Not a single person has been in the dash of a OBS truck?

 

Are you sure the motor is working correctly? When that resister goes it does strange things.

 

there is a write up about cleaning the evap core through the blower motor hole on fullsizechevy.com in the tech articles. also make sure the heater core cover on good and not cracked.

 

Do yourself a favor and replace the evap core.

 

Why would I do that if it's in perfectly good working order? It's just dirty that's all.

 

Yes sir, I bought the truck from dad so I know it's been progressivly getting worse over the years

 

If it was in perfectly good working order you wouldn't be having a problem with it. I was just trying to save you a lot of grief. I've seen all the cleaning products for evap cores and haven't seen any that work good enough. It will never be as good as a perfectly clean new one and plus the air is a lot more fresh when your done. If it were mine I'd change it. Just my opinion.