Originally Posted by
ladas
It seems odd that the effect is so noticable. You may want to have the AC running pressures check, typical systems running in your temperature zone would be at about 220 - 250 psi, maybe a little lower.
A high engine draw would indicate to me that maybe the pressure is running much higher than that !
How clean is the condenser ?, are the condenser fans running ? are they running the right way ? (yep I know this sounds silly, but I have seen it more than once).
A quick check, run the car, switch on the AC - observe the conditions, then get a garden hose, and spray cold water on the condenser coil and see if the engine drain seems less, if it does this will indicate high pressures in the system.
High pressures are caused (generally) by
1. Poor condensing, blocked or dirty condenser coil, poor condenser fans
2. Refrigerant overcharge
3. A blocked or semi blocked filter / drier, or a blockage somewhere else in the system.
There are a few other areas that can cause this, like faulty TX valve, but the above are the main ones.