It sounds like you refrigerant level is low. At rest, the pressure equalizes in the system. After you start it and turn the ac on, it pumps the refrigerant through the system and builds up pressure on the high side and pulls the low side down until it cuts off on the low pressure cycling switch. If you have to add to the system, then you've got a leak somewhere.
Because it also starts the air conditioning compressor which cycles on and off loading up the engine which changes the idle
The air conditioning compressor is belt driven from the engine. While compressor is on it adds another load to the engine. Therefore; yes it does require additional fuel to be used to compensate for the additional engine load.
The 2003 Pontiac Montana air conditioning compressor condensation drain begins on the bottom of the air conditioner compressor. The drain goes from the compressor to the bottom of the engine compartment.
The 2001 Dodge Dakota air conditioning drain hose is located on the bottom of the air conditioning compressor. The drain hose leads from the compressor to the bottom of the engine compartment.
Bottom, front, passenger side of the engine.
If the compressor is not engauged, it is ok.If the compressor is not engauged, it is ok.
Because the air conditioning compressor, is run from a pulley off of the engine. This puts an additional load on the engine, which causes more fuel to be used.
The 1990 Ford E1 50 air conditioning compressor relay is located in the fuse box. The fuse box can be found in the engine compartment.
the load of the AC compressor slows the engine
The compressor is probably froze up.
at the bottom pass. side of engine compartment
Could be your ac compressor is going or gone, probably gone.