Have just purchased a 1991 firebird v6, the problem is that the aircon doesnt work, if you short out the low pressure switch the pump cuts in, indicating that there is low pressure in the system.
In the passenger footwell I notice that the sound proofing was soaked in an oily type substance, could this be a possible leak on the aircon system ?
Has anyone got any diagrammes for the aircon system as haynes not much help.

Any help would be most apprieciated,

Thanx

 

for diagrams, you would probably need to get a helms manual, or PM Vader here, he always has neat pictures of stuff.

I've never heard of a a/c coolant leak, inside the car, I guess its possible if some how it was leaking into the blower case and then down the floorboard. Get a vacuum pump and try to vac the system down, if you cant get a good vacuum, you have a leak. when it comes to a/c systems I usually have a shop I trust work on it, as I dont have the necessary tools to do the job right

 

if you are absolutely positive that it isnt coolant then what you are feeling down there is probably refrigerant oil that has leaked out with the system charge. it sounds like you have a leaking evaporator. crawl under the passenger side and take a look at the condensate drain from the evap housing-its a small tube that sticks out of the firewall and try to see if the same oily poop has been draining out there too. you need to find a shop that can inject flourescent dye into the system, leave it in for a few days, a week, then have the same shop blacklight the entire system. your leaks will be fairly unmistakeable using this method.