So how much gas am I going to save... If Any?

[Nitrogen]

The fan blower for my AC just up and died on my way home from work today.

Any of you fine folk have any idea how much something like this costs to get fixed?
Something tells me it's more than I can afford at the moment anyway.

So, by not running the AC until I can afford to get this fixed, how much money am I going to save?
 

[Ex-MA Hole]

Depends on your driving...from what I know/ read/ have heard, if you are on backroads, windows open are better for mileage, but once you hit highways speeds, the wind resistance due to the air rushing into the open windows causes more fuel degradation than having the A/C on....

[Tallpine]

You'll save quite a bit if it gets too hot to drive anywhere 

[cassandra and sara's daddy]

what is this air conditioning in cars.......

[Gewehr98]

This was the subject of a Mythbusters episode.

Summary:

Windows down vs. air conditioning
"Urban puzzle": it is more efficient, on a hot day, to run with the A/C on and windows up than to run with windows down (b/c of increasing car's drag).

Computer-based mpg measurements: * 11.7/11.8 with A/C on and windows up * 11.7/11.8 with A/C off and windows up * 11.3 with A/C off and windows down

So, according to the computer, it's better to use A/C with windows up.

This was too quick and easy for TV, so they decided to stage a seven hour marathon, race-til-you're-empty duel, with Jamie driving an SUV with A/C on and Adam driving an SUV with windows down. Though, once the safety inspector intervened, it was no longer a seven-hour marathon, it was a bit slower (45mph instead of 55mph), and a lot shorter (only 5 gallons each).

Jamie's A/C car ran out of gas first -- Adam's windows down SUV ran for another 30 laps -- completely contradicting the computer mpg estimate. Computer estimate based on air flow into the engine, so it would appear that it is unable to properly model the difference between A/C and windows down.

Mythbusted

IOW, the horsepower drag via the air conditioning compressor compromised gas mileage more than the aerodynamic drag of open windows.

[Angel Eyes]

This was the subject of a Mythbusters episode.

Summary:

Windows down vs. air conditioning
"Urban puzzle": it is more efficient, on a hot day, to run with the A/C on and windows up than to run with windows down (b/c of increasing car's drag).

Computer-based mpg measurements: * 11.7/11.8 with A/C on and windows up * 11.7/11.8 with A/C off and windows up * 11.3 with A/C off and windows down

So, according to the computer, it's better to use A/C with windows up.

This was too quick and easy for TV, so they decided to stage a seven hour marathon, race-til-you're-empty duel, with Jamie driving an SUV with A/C on and Adam driving an SUV with windows down. Though, once the safety inspector intervened, it was no longer a seven-hour marathon, it was a bit slower (45mph instead of 55mph), and a lot shorter (only 5 gallons each).

Jamie's A/C car ran out of gas first -- Adam's windows down SUV ran for another 30 laps -- completely contradicting the computer mpg estimate. Computer estimate based on air flow into the engine, so it would appear that it is unable to properly model the difference between A/C and windows down.

Mythbusted

IOW, the horsepower drag via the air conditioning compressor compromised gas mileage more than the aerodynamic drag of open windows.

So they compared the fuel mileage of two different vehicles?  If so, I don't think they proved anything.  Even with identical specs, two SUVs are not going to get the same mileage.

They should have run one SUV with A/C on & windows up, refueled, then run it again A/C off & windows down.

[The Annoyed Man]

Is the blower motor dead?Or is it a bad relay/dash control head/blower switch?Or does it work just on high-w/no low speeds?

[Gewehr98]

Hey, I'm not the producer of Mythbusters.  They did it the way they did it with two identical vehicles, and you're more than welcome to drop the show a note telling them of the error in their scientific ways.  It wouldn't be the first time that's been done...

[Declaration Day]

Blower motors aren't all that pricey, usually well under $100.  The work can be a different story.  If you have a Ford truck, you can pop the hood and it's mounted to the firewall with three screws.  On most vehicles, you'll have to pull the big, black, plastic, weird-shaped "air box" from under the dash.  If you're lucky, it might have it's own separate access panel.

Either way, it's not rocket science.  Buy a motor, a Haynes manual if you need it, and git 'er done.

[Manedwolf]

Depends on your driving...from what I know/ read/ have heard, if you are on backroads, windows open are better for mileage, but once you hit highways speeds, the wind resistance due to the air rushing into the open windows causes more fuel degradation than having the A/C on....

I think Mythbusters pretty much busted that one.

[Boomhauer]

Well, the mythbusters experiment...are they taking into account that two people drive differently? My father can wring all the MPGs possible out of a vehicle, yet I cannot do nearly as well, even if I do everything he tells me to. Did they switch vehicles and repeat?

I can see how there might be a very slight difference...I cannot see how they got 30 more laps just cause the windows were down.

[Nitrogen]

It's a HOnda Accord, 03.  I'm pretty sure its not the switch, or the fuse.

The dang thing just up and suddenly died.  No warning noises, scraping, etc... just died.

[drewtam]

Another complaint about the mythbusters' experiment is that they used an SUV. A truck engine with 200-250hp doesn't notice the drag of an 10hp ac compressor as much as a 100hp economy car engine.

[never_retreat]

Your going to want to pull the wiring harness of the motor and check for voltage before you do anything else. I seen quite a few switches on the dash go bad.

You know you work with a bunch of electricians if you hop in a truck one day and find an ivory wall switch on the dash controlling the fan. I wish I had taken a picture at least to hang on the wall in the garage. And who said rednecks did the classiest auto repairs.

[Nitrogen]

Your going to want to pull the wiring harness of the motor and check for voltage before you do anything else. I seen quite a few switches on the dash go bad.

You know you work with a bunch of electricians if you hop in a truck one day and find an ivory wall switch on the dash controlling the fan. I wish I had taken a picture at least to hang on the wall in the garage. And who said rednecks did the classiest auto repairs.

I have no idea where the motor is (yet)

This car is annoying as the climate console is part of the radio, or, was before I got an aftermarket radio attachment.  And no, that didn't cause it.  The buttons still work.  In fact, if I turn the AC on, the compressor still engages, but the fan just doesn't turn on, so I'm pretty sure its not the switch at the dash.

I even plugged the old radio/climate control console back in, and got the same thing.  I'll check into this and see if I can figure out where the motor harness is and all that.

[mfree]

i have an instant mileage gauge in my truck (added aftermarket).

I can be heading down the highway in a level cruise, getting 29mpg. Flip on the AC, drops to 26-27.

Now, my AC compressor is the same as everyone else's, but it's a much bigger portion of my 120hp than y'all's too

By the way, First thing you want to do is see if you can get to the cage from the floorboards, and try and spin the motor. If you run on recirc, you could have sucked something in. Also, if the resistor pack has fried (VERY COMMON), you'll get nothing until you hit full, which bypasses it.

[Manedwolf]

Your going to want to pull the wiring harness of the motor and check for voltage before you do anything else. I seen quite a few switches on the dash go bad.

You know you work with a bunch of electricians if you hop in a truck one day and find an ivory wall switch on the dash controlling the fan. I wish I had taken a picture at least to hang on the wall in the garage. And who said rednecks did the classiest auto repairs.

I have no idea where the motor is (yet)

This car is annoying as the climate console is part of the radio, or, was before I got an aftermarket radio attachment.  And no, that didn't cause it.  The buttons still work.  In fact, if I turn the AC on, the compressor still engages, but the fan just doesn't turn on, so I'm pretty sure its not the switch at the dash.

I even plugged the old radio/climate control console back in, and got the same thing.  I'll check into this and see if I can figure out where the motor harness is and all that.

The switch to the integrated radio/climate/etc was one of the stupidest things Honda did, total violation of the KISS principle and Sochiro Honda's maxim of "Man Max, Machine Min". It's a pain in the ass to deal with, and yes, the aftermarket "replacements" can cause problems. I'm very glad I have a 2000, before they did that nonsense with the panel. I can swap in any new aftermarket double-DIN stereo head I want, and it doesn't touch any other vehicle control system.

BTW, unless they drastically changed the design, most of the A/C system is under the right side of the dashboard, accessible by removing the lower bezel (pops off) and perhaps glove box. Find the fan housing and listen to it with a stethoscope when you turn it on, see if you hear a hum. If you do, the fan could be jammed. If you don't, it's not getting power or the motor is completely out, so you've eliminated one cause and can move upstream. Just pulling the harness and testing for power might not work, because there could be a chip somewhere that won't deliver power unless it detects the proper resistance of the motor it wants to be there or something. Besides, I like noninvasive solutions first, and stethoscopes are great for that sort of thing!

(It's also unlikely that you could have sucked anything in, as Accords have a two-piece HEPA filter on the recirculation intake before it gets to the fan.)

[Nitrogen]

Oh, rockin!  I'll check on this after work and report back.

Thanks folks.

[mfree]

scangauge.com

plug in, turn on, input size of engine, drive off. ~$170, but I figure I'll make that back within a year if I can keep up the 28-29mpg averages. Usually I'm driving around in the high 26s.

[Brad Johnson]

Rule number one.  Always check the fuse first...

They should have run one SUV with A/C on & windows up, refueled, then run it again A/C off & windows down.

Done.  They revisited the myth after everyone start screaming that "it just can't be true?!"  Same result.

Brad

[Nitrogen]

Rule number one.  Always check the fuse first...

I did