ENGAGEMENT of HVAC FAN precipitates POWER LOSS...

[crispone]

Anybody else notice that turning on the FAN (dial, in my case... for HEATER) causes a DISTINCT "KICK" (drawing power) like you feel when the A/C is turned on (compressor clutch engaging...) EVEN WHEN THE A/C IS OFF?

I notice that the car "idle/load" is INCREMENTALLY increased when the FAN is turned on... (ONCE AGAIN! EVEN WITH THE A/C "OFF")


Has anyone ELSE noticed this?


(I believe my A/C pump was KICKING IN sometimes last year EVEN WITH THE BUTTON FOR A/C NOT illuminated signifying it was "OFF", but it did it for a few days or week or so... and then it "stopped". Kind of like the compressor was "stuck" in the engaged position...)

Any thoughts?


-crisp

[kingkakyle]

happens to me too...whenever i turn my fan on or ac i lose a lot of power and my tach goes up
so when i pass people i have to turn off the fan or ac otherwise i struggle a bit lol especially when its all the way up

[Sebas007]

Do you really feels the difference ? So you say that in summer on the drag strip...when the engine is boiling...it's better not open the fan on and let the hot air inside the engine bay then to put it on to evacuate the hot air ???

[PXLpainter]

Do you really feels the difference ? So you say that in summer on the drag strip...when the engine is boiling...it's better not open the fan on and let the hot air inside the engine bay then to put it on to evacuate the hot air ???

Hehe - wrong fan Sebas!

He's talking about the HVAC fan on your center console - cabin air.

I've never noticed it before - but I will check it out. I don't have the "knobs" in the SLE though - not sure if that makes a diff. tho'

[Down2TheC]

I think crisp is growing in his back yard.

[data xXx]

I noticed after about 13,000 miles that my 04 3.3 kicks a lil whenever I turn on the a/c or heat fan. I think that since Toyotas are more efficient than other cars, the alternator generates juuuust enough power for normal functions. For example, I had a amp and sub combo in my 91 maxima, swapped it out into the solara, and my headlights dim when the bass hits.........

And that's about the same time I noticed them cheesy Bridgestone Turanza's it came with as well.
I dunno man, sometimes I feel like the car magazines should test out a new car for like a year before giving out its review.
Next time I'm gonna lease a car before gettin it, that way we dont gotta gotta pay for these lil problems AFTER they come up.

[crispone]

I'm thinking a dual battery system for the stereo... but I don't know if the "deeper reserve/cycling" can be "configured" to "buffer" the draw on the alternator enough to eliminate this power robbing characteristic.

Is the draw "subtle"?

YES.

Does it STILL make enough of an "effect" to make a difference?

YES.

Why?

Because you are GAINING a "value added" amount of Horsepower when you FEEL the gain through the seat of your pants... therefore, if you FEEL the LOSS as WELL... then it is substantial enough to be a "DEMERIT added" power loss. Primarily, with respect to RESPONSE.

As for crisp, I'd like to see the "dip" eliminated.


Otherwise, I'll keep "leaning forward to push the TURBO boost button" accordingly... ...heh heh heh...


-crisp

[crispone]

I think crisp is growing in his back yard.

...why would I get LARGER in my backyard?





-crisp

[kingkakyle]

i think it takes a toll more on my i-4 engine
when my fan is on especially with the AC i have the hardest time passing people unless i really put the pedal to the metal, so to speak

[funboy102]

Yes, I notice when I press the AC button, the more power is drawn from the engine.

No I do NOT notice more power being drawn from the engine with just the fan on, no AC.

(for the record, you know if you have it set at front defroster, and then the air selector to fresh air, as oppose to re-circulatory air, and then turn on your fan, A/C will automatically turn on, even though the light on the A/C button won't turn on? <--- Does this wording make sense to you?)

[crispone]

Yes, I notice when I press the AC button, the more power is drawn from the engine.

No I do NOT notice more power being drawn from the engine with just the fan on, no AC.

(for the record, you know if you have it set at front defroster, and then the air selector to fresh air, as oppose to re-circulatory air, and then turn on your fan, A/C will automatically turn on, even though the light on the A/C button won't turn on? <--- Does this wording make sense to you?)

Hmmm... I DO know that if the fan is ALREADY on (no A/C) and I select WINDSHIELD or WINDSHIELD AND FEET, the RECIRC will automatically go OFF and switch to FRESH...

I'll try YOUR scenario next drive...


-crisp

[jhenty]

It all has to do with the electrical system. When you turn the fan up you are merely switching resistors in a circuit to allow the blower motor to run faster. By creating less resistance you are using more current. Engine size would not really affect this. I notice with toyotas I've owned or driven that changes in electrical draw always have a noticeable effect on the car, must just be the way they are wired.

[crispone]

It all has to do with the electrical system. When you turn the fan up you are merely switching resistors in a circuit to allow the blower motor to run faster. By creating less resistance you are using more current. Engine size would not really affect this. I notice with toyotas I've owned or driven that changes in electrical draw always have a noticeable effect on the car, must just be the way they are wired.

This is the first TOYOTA (out of 10 or more...) that I have EVER noticed this much power draw from the motor over anything OTHER than the AC being activated... NEVER this much affect from JUST the FAN.

Otherwise, I agree with the electrical draw you speak of. The more ELECTRICAL load... the more MECHANICAL resistance through the "generator" (alternator).


-crisp

[Sebas007]

Do you really feels the difference ? So you say that in summer on the drag strip...when the engine is boiling...it's better not open the fan on and let the hot air inside the engine bay then to put it on to evacuate the hot air ???

Hehe - wrong fan Sebas!

He's talking about the HVAC fan on your center console - cabin air.

I've never noticed it before - but I will check it out. I don't have the "knobs" in the SLE though - not sure if that makes a diff. tho'

I know Jeff, didn't understand what I was trying to talk about on my post...yeah I was talking of the HVAC, what else ?? Anyway, I do not have that SLE HVAC...



So Crisp you are sure that when the fan only it's ON, some power is lost ?? Fan only is almost always ON isn't it ?? In winter to push the hot engine air inside the cockpit...in summer (maybe more power drain) the fan push the cold air of the A/C. I just ask again because I wanna be sure what to do next 1/4 run...I closed everything in all my runs. But I was thihkning I could put the fan to MAX and air to RED HOT to eliminate more hot air under he hood...to help the SRI breathing.

What you would do ?

[PXLpainter]

Do you really feels the difference ? So you say that in summer on the drag strip...when the engine is boiling...it's better not open the fan on and let the hot air inside the engine bay then to put it on to evacuate the hot air ???

Hehe - wrong fan Sebas!

He's talking about the HVAC fan on your center console - cabin air.

I've never noticed it before - but I will check it out. I don't have the "knobs" in the SLE though - not sure if that makes a diff. tho'

I know Jeff, didn't understand what I was trying to talk about on my post...yeah I was talking of the HVAC, what else ?? Anyway, I do not have that SLE HVAC...



So Crisp you are sure that when the fan only it's ON, some power is lost ?? Fan only is almost always ON isn't it ?? In winter to push the hot engine air inside the cockpit...in summer (maybe more power drain) the fan push the cold air of the A/C. I just ask again because I wanna be sure what to do next 1/4 run...I closed everything in all my runs. But I was thihkning I could put the fan to MAX and air to RED HOT to eliminate more hot air under he hood...to help the SRI breathing.

What you would do ?

Sebas - I don't know how they build the cars up their in the Great White North, but they haven't used heat from the engine compartment for cabin heat in decades! (since maybe the Model T?)

They route water from the engine through a heater core and a small fan then blows through that small radiator - so basically its like a wall radiator in an older house. That's why it take awhile for your car to warm up before feeling the heater - but it's not engine compartment air re-routed to the cabin.