I understand that wtih the AC on the engine needs to idle higher but when I just turn on the normal climet fan [usually on heat] it seems to make the idle go up and down. Why?

 

How do you recieve power other than your battery? Well from the engine spinning. The alternator needs to be spun a bit faster to start other things such as A/C, Climate fan, sound systems, etc. . . it's jut want cars do. lol :? I could be totaly off, but oh well.

 

Fixtion is correct. I don't know what the temperature setting has to do with it though. Hot or cold should require the same amount of electricity.

 

turning the fan on increases the load on the alternator, the ECU will bump up the idle to compensate for the load.

just like when you turn on the AC (or if you moved the air flow selector to the windshield/floor or windshield setting. this turns on the ac automatcally.)this puts a load on the motor and the ECU will bump up the idle to compensate.

you said the temp was on heat, but where was the air blowing to???

 

^^^^^and BINGO was his name o^^^^

 

I highly doubt that the electricity needed to run the fan ris what makes the idle rise. If that was true why dosn't the idle remain high? Incase you haven't noticed turning the fan on makes the idle intermitenly switch between normal and like 1000 rpms. Aditionally I can plug in a 200 wat inverter the idle never changes.

 

ever since I put in ground wires.. I never see idle jumps (rpm needle rising) unless I put on my a/c.....

 

thats a normal car function

 

You RPM's could be jumping because of emission issues. When you vehicle is running cold exhaust is worse than when you are warm(because you aren't burning all the gas). What's probably happening your emission sensor is saying that you need to warm up quicker because of a larger drag (turning on the blower) for emission issues.

Most Toyota Vehicles do this because they are all ultra-low emissions vehicles.

 

If you have it blowing air on your windshield (even if you haven't pushed the windshield defroster button) it's running the A/C compressor too, so maybe that's what you're experiencing.