Vibe 2007 - fan puts high load on engine

[mdu6]

I owned a 2003 Vibe but on the 2007 (same configuration), the fan (even at low setting - no AC) seem to put a large load on the engine/electric system.Waiting at a stop light, with the feet on the brake, turning the fan ON puts somewhere like 200RPM on the engine, you feel the strain put on the engine to supply the power ... This was present on the first day I took the car. I reported it to the dealer who just said something like ¨you know these are very large fans ..."I just wonder if others are seeing the same, thanks

[j42.snyder]

Sounds more like the A/C is being engaged to me. Is the air mode set anywhere between the floor and defog? As soon as mine went towards defog at all, it would engage the A/C "automatically". I disabled this feature - and now have full manual control over A/C usage.Check it out and see. The A/C light won't come on - but move the selector towards the upper dash vents, and see if it changes. It also won't engage the compressor when the fan is off - which could explain this a bit.I don't know about the 1st gen cars, but 2009-10's have a PTC heater inside the ventilation assembly that's supposedly powered when the temperature control is turned all the way to "hot". I haven't noticed a change with this either working or not - but its draw would be strictly electrical. What you're experiencing sounds much more like the compressor engaging.I modified my friend's '06 to lose this "automatic" A/C feature. Much easier than on the '09's. Around here at this time of year it's often helpful to keep some heat on the front glass - but still dry enough that the A/C isn't necessary. At times where it is beneficial, I just hit the switch and it helps dry thing up nice and quick. I just don't like the compressor using more gas than necessary if I don't need it. At our prices here (last tank cost me $1.11/liter or about $4.20/gal), I don't need anything being wasted. I go through more than a tank a week as it is!

[mdu6]

Thanks - I will check it out.How did you disable the AC to come on this way ?

[TONY TAT2]

You can pull the conector off the compressor,or the pressure switch on the line. That will keep the compressor from engagen.It might still cause a high idle tho. Easy to check ,with the car warmed up & at normal idle turn on the ac or defroster ,if the car idles higher its controled by the ECM & AIC.The fan may or may not come on also,depends on how its set up from the factory. My 85's idle drops like a brick when the coolen fan kicks in,the alt really takes a big hit then.

[j42.snyder]

I wouldn't do anything to completely disable it. There are times where you'd like to use it, without going under the hood to figure out what you disconnected previously. Also, you will get corrosion on connectors left unhooked outside of the passenger compartment - not recommended.On the 1st gen Vibes, (if I remember correctly), there is a connector going to the top of the heater controls inside the dash with a yellow and black wire. This is wired in parallel with the "A/C" switch up higher on the dash. When the mode switch below is turned towards "defog", a switch is closed forcing the A/C ON - even though it isn't indicated by the light in the above switch. All you need to do is disconnect this plug on the heater controls - and voila! No more "forced" A/C use on defog - but you will still have full access to it using the A/C button on the dash at any time.It's a little bit of work getting in there, but I think it took me less than 15 minutes on my friend's car to do it - and that was the first time trying. You just have to be VERY careful disengaging all of the little plastic tabs on the dash trim pieces to prevent breaking any.On the '09-'10's, it's not quite so straight forward. There's a wire you can cut in the harness to have the same effect behind the heater controls. I cut mine - but in a spot that I could easily splice it back together if desired. Again, it is a yellow wire. I posted a "how to" on this last year I think.I found the details somewhere online as to how to open-up the dash on the 1st gen cars - so do some searching if you want to try it. At least it's very easy to go back if you want - just a simple connector.John

[lovemyraffe]

The A/C unit is engaged when you turn on the defroster for a good reason. It helps to keep the seals lubricated and the whole thing from freezing due to cold temperatures during the winter. There are some who have disabled the A/C and haven't had problems. I personally wouldn't do it. I have seen issues in the spring when people want their A/C working again.

[mdu6]

Thanks - I will check it out.How did you disable the AC to come on this way ?

[mdu6]

To confirm - Yes this is what is happening - as soon as the airflow selector includes some defrost the AC compressor kicks in. I will first make some test to see if it makes a difference over a week - since I was normaly always leaving the selector to the next to last position (which include defrost ...) - thanks

[djkeev]

Quote, originally posted by lovemyraffe »The A/C unit is engaged when you turn on the defroster for a good reason. It helps to keep the seals lubricated and the whole thing from freezing due to cold temperatures during the winter. Well.......... Lubricating the seals is a side benefit for sure, but not the reason the AC runs when the defroster is turned on. Also the gas in the AC hasn't any fear of freezing! R 134a (Tetrafluoroethane)Has a freezing point of -142 F !! If it is that cold, I ain't gonna go outside!!!The real reason is to take advantage of the dehumidifying properties of Air Conditioning. As soon as the compressor kicks on the humidity rapidly gets sucked out of the cabin, the air coming out of the defroster vents is now dry air and not the moisture laden air so common when you've got when window fogging happens. All of that moisture got caught on the AC coils as it passed through them.Dave

[Sublimewind]

Quote, originally posted by mdu6 »To confirm - Yes this is what is happening - as soon as the airflow selector includes some defrost the AC compressor kicks in. I will first make some test to see if it makes a difference over a week - since I was normaly always leaving the selector to the next to last position (which include defrost ...) - thanksANY time you select any of the defrost functions it will cycle the A/C pump.. This is MORE to remove moisture in the air, de-FROSTing (frost being moisture) becomes easier.. A great side benefit if it is cycling the pump and lubricating the seals and bearings.. If it's dragging your car down like that, there could be an issue with the A/C system, because mine seems "seamless" to me, on ANY of the A/C functions..

[ramenboy...]

Quote, originally posted by mdu6 »I...I reported it to the dealer who just said something like ¨you know these are very large fans ..."amazing how lazy these service managers/depts can still be. truly amazing.anyways, like sublime and everyone said, the a/c kicks in when the defroster is engaged, so the 'defrosting air' entering the cabin will be drier; the bi-product is no moisture in the cabin/on the windows, so they'll clear.check to make sure a/c isn't engaging when just the fan is running.good luck

[lovemyraffe]

Quote, originally posted by djkeev »Well.......... Lubricating the seals is a side benefit for sure, but not the reason the AC runs when the defroster is turned on. Also the gas in the AC hasn't any fear of freezing! R 134a (Tetrafluoroethane)Has a freezing point of -142 F !! If it is that cold, I ain't gonna go outside!!!The real reason is to take advantage of the dehumidifying properties of Air Conditioning. As soon as the compressor kicks on the humidity rapidly gets sucked out of the cabin, the air coming out of the defroster vents is now dry air and not the moisture laden air so common when you've got when window fogging happens. All of that moisture got caught on the AC coils as it passed through them.DaveI do agree with you. There are other reasons besides keeping the seals lubricated, like you said, to take advantage of the dehumidifying properties. I wasn't saying that the R134a was going to freeze. I was trying to say without getting into the hows of seeing the A/C unit lock up due to not being used/lack of air flow.

[djkeev]

Quote, originally posted by lovemyraffe »I do agree with you. There are other reasons besides keeping the seals lubricated, like you said, to take advantage of the dehumidifying properties. I wasn't saying that the R134a was going to freeze. I was trying to say without getting into the hows of seeing the A/C unit lock up due to not being used/lack of air flow.Gotcha!! Seize rather than freeze! Dave