I have a 1999 ford ranger XLT 4.0 V6 4wd and everytime i turn the heat or ac on the engine tends to idle up to about 2-2.5k for a few seconds then go back to normal. i was curious if anyone else has encountered this and has a solution

 

Those put a load on the engine so they have a switch that sends a signal to your computer to add a little more fuel.
2k to 2.5rpms is a little high I guess. It could be the voltage or amperage signal is a little more than normal.
Im just getting back into rangers so I couldn’t describe the system but the amperage is either finding less resistance
so the signal is higher than normal or something similar. Cabin fan motor resistors go. That’s the biggest electrical draw
when the switches go a/c or heat.