Random Thoughts... [Automotive Edition]

[CraigB]

On the topic of A/C and defrost. Dad's 2010 GMC Sierra will not allow you turn the A/C on with the defrost below 45F. You press the button, the light comes on for a split second, then blinks a couple times and shuts off.

 

[prizrak]

Not a problem for my truck.

It can carry about any size tire and wheel I can fit to the truck. Though I really want to change it to an in-bed carrier.

The XJ can carry an identical spare wheel to the stockers (and did) but the spare tire well won't fit my 17x7s. I have to get a spare stock tire and wheel (15x5) eventually. Heck of a 'space saver' at that point.

It's finally hit 100F here, guess I get to go see just how capable the repaired AC in the truck is.

Oh I got room for a full sized spare, the problem is which spare do I carry? 18x8 or 18x8.5?

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Wasn't it actually proven in the Mythbusters revisit? Also, a lot depends on your vehicle's aero.

I believe it was, from anecdotal there is a noticeable difference in the Z's acceleration at high speed with windows open or closed.

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Defog logic wasn't common until the mid to late 90's me thinks. My mid-trim Saturn with working AC did not have it and the escort definitely didn't. I can't recall if the SHO's automatic system did...I presume so given its automatic nature.

I knew defogging works without AC but its not ideal if its summer or spring because for effective defogging without AC, I've found that one has to turn on the heat. Not fun.

Some models don't light up the AC indicator when defog logic is active: initially they found that people would see the indicator, freak out (because it was winter or whatever...they figured AC = cold) and turn it off....resulting in slower/nonexistent defogging depending on how they had the temp knob turned to.

On some models, one can toggle defog logic off so you don't have to turn off the AC each time if you don't like it...it would then revert to just pushing air to the windshield old school style.

Subaru turns on the A/C for defogger, Z does as well but ofc Z has a fully automated HVAC.

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Perhaps the Saab is an outlier then - but the consensus here is that it is risky at best for most cars.

For that matter, is it just gasketted on or is it actually glued on? Gasketted ones are easy, it's the glued on ones that you might as well not bother with.

Confirmed, my friend actually bought a whole hatch for his 240 because his rear windshield was fucked up, it was easier and cheaper than just the window...

 

[rickhamilton620]

http://www.discovery.com/tv-shows/mythbusters/mythbusters-database/ac-vs-open-windows.htm

I read the comments though and they supposedly did it again and the AC car was more efficient.

Edit: *reads previous posts*...I suck at reading....

 

[93Flareside]

So, I would imagine that certain locations for rental car facilities get loaded up with one way drivers meaning one location has too many cars. Surely there's a job where somebody ends up having to move cars between facilities. How does somebody get that job? Does UHaul deal with the same thing?

 

[Spectre]

In my current car, I just tried an experiment. When I switch from floor, to dash, to windshield, I don't really hear anything significantly different. When I switch to the AC modes (AC or Max AC) I definitely hear something coming from "behind" the dash. Am I imagining it? Is the AC really on when I turn on the windshield vents? 99% of the time, I drive with dash and windshield turned on, with the fan on 1.

Noise in the dash is not a good way to determine if the AC is running. That could just be the system routing airflow through different ducts - and usually is. The best way to see is to open your hood and locate the AC compressor. If your AC is off, the center of the pulley, where the clutch is located, will not spin. If the AC is running, the whole assembly will spin together. You can then experiment with modes to see when your compressor kicks on and off.

Defog logic wasn't common until the mid to late 90's me thinks. My mid-trim Saturn with working AC did not have it and the escort definitely didn't. I can't recall if the SHO's automatic system did...I presume so given its automatic nature.

I knew defogging works without AC but its not ideal if its summer or spring because for effective defogging without AC, I've found that one has to turn on the heat. Not fun.

Some models don't light up the AC indicator when defog logic is active: initially they found that people would see the indicator, freak out (because it was winter or whatever...they figured AC = cold) and turn it off....resulting in slower/nonexistent defogging depending on how they had the temp knob turned to.

On some models, one can toggle defog logic off so you don't have to turn off the AC each time if you don't like it...it would then revert to just pushing air to the windshield old school style.

"Defrost logic" was *extremely* common in USDM air conditioned cars until after the oil 'crises'. Even after those events it remained very common. But first, let's address one thing.

Rick, here is a 1964 Cadillac Eldorado, displaying the first in the world automatic climate control's panel:
http://si.wsj.net/public/resources/images/BN-AW427_1217My_M_20131223112412.jpg

Here is a manual climate control panel from the 1976 Chevrolet Nova, one of Chevrolet's cheaper cars:
http://www.ctcautoranch.com/Misc. P...2/1976 Chevrolet Nova Heat and AC Control.JPG

And what would be the classic 80s and beyond GM manual climate control panel; this particular example would be from a 77 Malibu:
http://www.ctcautoranch.com/Misc. P...1977 Chevrolet Malibu Heat and AC Control.JPG

Wasn't just GM. Ford and Chrysler had similar controls. Here's one from an early Fox body Mustang:
http://i.ebayimg.com/00/s/MTI4MFg5NjA=/z/O80AAOxyJ-FRk9up/$(KGrHqN,!lMFEzJi2cN0BRk9upgQ7!~~60_57.JPG

And the classic 90s Ford climate control panel, this from a 90-93 Fox Mustang:
http://i.ebayimg.com/00/s/MTIwMFgxNjAw/z/t0MAAOxy3yNTe3Zn/$_57.JPG

Notice the one thing they all are 'missing'? An 'A/C' button. There is no button to manually turn the compressor on or off. Notice what else they're missing? An 'A/C On' light.

See, back when US cars first got air conditioning systems, they had real engines, instead of metal casings wherein two asthmatic gerbils raced about in wheels. Running the compressor took such a small percentage of the engine's available power most people didn't notice. There was no need to inform the driver that his compressor was engaged because it made no difference in normal usage. These were almost invariably wired (even the manual controls) to turn on the compressor when the defrost function was selected. This was not only to dehumidify the cabin but to ensure that lubricant was circulated in the AC system so it would not dry out and fail come spring. The automatic systems went one step further - the system ran the AC even when the heat was on for those same reasons. Since Jaguar cloned/bought in the Cadillac automatic climate control for the XJ, that's something I'm very familiar with. It's amusing when new owners of a classic XJ or XJS freak out about the car engaging the compressor in the depths of winter all by itself. (Unlike the American cars the system came from, the XJ S2/3 and early XJS don't have idle up systems so you can actually tell by the tach when the compressor engages.)

Anyway, flash forward to the post oil crises market and you suddenly have people buying little ecoshitboxes with horsepower measured in the mid double digits where engaging the air conditioning meant that your horses suddenly escaped. In some it was so bad, you'd think you'd run into a wall or lost half your engine. Manufacturers began equipping vehicles with AC compressor switches to allow the driver to control the compressor directly and added lights to warn the driver that turning the AC on meant that you had no power available to you. Most of the American offerings that came with V6s and V8s (even as options) did not convert and retained the older style controls and what you called 'defrost logic'. My 95 F-350 does the exact same thing when defrost is selected as my 86 F-150 did, which did the exact same thing as my 68 Caddy did. I don't have to push a button, no light comes on, but the compressor engages. "Defrost logic" has been around for almost as long as car air conditioning has. Lack of this function is the exception and always has been, not the rule.

Further, if your car doesn't have this function, that's a pretty good sign that it's an underpowered pile of garbage. Also that you need to remember to turn on the air conditioning regularly during your winter to make sure lubricant circulates and seals don't dry out.

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On the topic of A/C and defrost. Dad's 2010 GMC Sierra will not allow you turn the A/C on with the defrost below 45F. You press the button, the light comes on for a split second, then blinks a couple times and shuts off.

All it's doing is telling you that it thinks you're an idiot and should not be trying to cool the interior further.

I remember the first time I saw that in a friend's company Silverado, we had to pop the hood to tell but lo and behold it's still engaging the compressor in defrost mode.

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So, I would imagine that certain locations for rental car facilities get loaded up with one way drivers meaning one location has too many cars. Surely there's a job where somebody ends up having to move cars between facilities. How does somebody get that job? Does UHaul deal with the same thing?

UHaul and other rental companies deal with it by offering special rates to renters to take the vehicles somewhere else. Failing that, if there are enough cars they will hire a transport company to truck them all to a more useful location. Sometimes someone from the destination office will be flown out to collect a car if there's only a couple.

 

[CraigB]

All it's doing is telling you that it thinks you're an idiot and should not be trying to cool the interior further.

I remember the first time I saw that in a friend's company Silverado, we had to pop the hood to tell but lo and behold it's still engaging the compressor in defrost mode.

It sure didn't seem like the A/C was engaging. The windshield fogged up and it was difficult to get it to unfog.

 

[Spectre]

It sure didn't seem like the A/C was engaging. The windshield fogged up and it was difficult to get it to unfog.

Might be broken, then. The 08 Silverado was absolutely engaging A/C for its defrost mode despite claiming on the panel that it was not.

 

[rickhamilton620]

Noise in the dash is not a good way to determine if the AC is running. That could just be the system routing airflow through different ducts - and usually is. The best way to see is to open your hood and locate the AC compressor. If your AC is off, the center of the pulley, where the clutch is located, will not spin. If the AC is running, the whole assembly will spin together. You can then experiment with modes to see when your compressor kicks on and off.



"Defrost logic" was *extremely* common in USDM air conditioned cars until after the oil 'crises'. Even after those events it remained very common. But first, let's address one thing.

Rick, here is a 1964 Cadillac Eldorado, displaying the first in the world automatic climate control's panel:
http://si.wsj.net/public/resources/images/BN-AW427_1217My_M_20131223112412.jpg

Here is a manual climate control panel from the 1976 Chevrolet Nova, one of Chevrolet's cheaper cars:
http://www.ctcautoranch.com/Misc. P...2/1976 Chevrolet Nova Heat and AC Control.JPG

And what would be the classic 80s and beyond GM manual climate control panel; this particular example would be from a 77 Malibu:
http://www.ctcautoranch.com/Misc. P...1977 Chevrolet Malibu Heat and AC Control.JPG

Wasn't just GM. Ford and Chrysler had similar controls. Here's one from an early Fox body Mustang:
http://i.ebayimg.com/00/s/MTI4MFg5NjA=/z/O80AAOxyJ-FRk9up/$(KGrHqN,!lMFEzJi2cN0BRk9upgQ7!~~60_57.JPG

And the classic 90s Ford climate control panel, this from a 90-93 Fox Mustang:
http://i.ebayimg.com/00/s/MTIwMFgxNjAw/z/t0MAAOxy3yNTe3Zn/$_57.JPG

Notice the one thing they all are 'missing'? An 'A/C' button. There is no button to manually turn the compressor on or off. Notice what else they're missing? An 'A/C On' light.

See, back when US cars first got air conditioning systems, they had real engines, instead of metal casings wherein two asthmatic gerbils raced about in wheels. Running the compressor took such a small percentage of the engine's available power most people didn't notice. There was no need to inform the driver that his compressor was engaged because it made no difference in normal usage. These were almost invariably wired (even the manual controls) to turn on the compressor when the defrost function was selected. This was not only to dehumidify the cabin but to ensure that lubricant was circulated in the AC system so it would not dry out and fail come spring. The automatic systems went one step further - the system ran the AC even when the heat was on for those same reasons. Since Jaguar cloned/bought in the Cadillac automatic climate control for the XJ, that's something I'm very familiar with. It's amusing when new owners of a classic XJ or XJS freak out about the car engaging the compressor in the depths of winter all by itself. (Unlike the American cars the system came from, the XJ S2/3 and early XJS don't have idle up systems so you can actually tell by the tach when the compressor engages.)

Anyway, flash forward to the post oil crises market and you suddenly have people buying little ecoshitboxes with horsepower measured in the mid double digits where engaging the air conditioning meant that your horses suddenly escaped. In some it was so bad, you'd think you'd run into a wall or lost half your engine. Manufacturers began equipping vehicles with AC compressor switches to allow the driver to control the compressor directly and added lights to warn the driver that turning the AC on meant that you had no power available to you. Most of the American offerings that came with V6s and V8s (even as options) did not convert and retained the older style controls and what you called 'defrost logic'. My 95 F-350 does the exact same thing when defrost is selected as my 86 F-150 did, which did the exact same thing as my 68 Caddy did. I don't have to push a button, no light comes on, but the compressor engages. "Defrost logic" has been around for almost as long as car air conditioning has. Lack of this function is the exception and always has been, not the rule.

Further, if your car doesn't have this function, that's a pretty good sign that it's an underpowered pile of garbage. Also that you need to remember to turn on the air conditioning regularly during your winter to make sure lubricant circulates and seals don't dry out.

Ahh! The more ya know I guess! Thanks!

 

[Spectre]

Ahh! The more ya know I guess! Thanks!

More to the point, you should assume that just because your Failturn and Failscort did something one way or lacked a feature that most cars did it that way. In fact, you should assume the exact opposite - something you have yet to learn.

 

[rickhamilton620]

More to the point, you should assume that just because your Failturn and Failscort did something one way or lacked a feature that most cars did it that way. In fact, you should assume the exact opposite - something you have yet to learn.

Yeahhhh...

 

[JimCorrigan]

I think she nailed us.

Car-review sites are like Man Thought Catalog. And how do I know they?re mostly men? Because if you post as ?Jon? to describe something as a ?MILF car? it?s a good bet, and the average poster will mention his wife?s usually ?sensible but soulless? car one sentence into his passionate, often sentimental, aesthetically attuned excoriation.

It?s as if, liberated, as they clearly feel in these spaces, these men still need to say ?I?m very manly, I have a wife? before they?re at ease using words like ?delightful? and ?disenchanted? and ?drab,? which they do.

You could put five dozen men in a house made entirely of brown corduroy and maybe one of them would call it ?drab,? but put those same men on a car-review website and they not only say ?the dashboard?s drab,? they?ll say, ?No one in their right mind puts all those buttons on a steering wheel! It?s too busy. It made me want to cry.?

Yes, they?ll rage about a car manufacturer no longer offering a manual option but they?ll also say, ?I?d have named it the JU-35. For Just Ugly? and, ?I tried to look at the interior on the manufacture?s website but I kept falling asleep.?

Hello, Oscar Wilde, you gearhead. Nice to meet you.

 

[NooDle]

Doesn't turning on the AC mean the engine has to work a bit harder, resulting in a slight drop in idle rpm? It's quite noticable on my car, but that may be because the AC compressor is about as big as the engine.

Also, my fullsize spare steelie is probably smaller than some of your space savers. Small=awesome

 

[Spectre]

Doesn't turning on the AC mean the engine has to work a bit harder, resulting in a slight drop in idle rpm? It's quite noticable on my car, but that may be because the AC compressor is about as big as the engine.

The drop in idle RPM varies by motor, and many of the older cars had a solenoid to idle up the engine slightly to compensate so you wouldn't actually notice. Yes, even with a carburetor. Modern cars do it with their idle control system. My 7.3 simply doesn't notice and doesn't have to idle up. The 4.2L Jag six drops about 150rpm, no idle up solenoid. My former co-worker's Geo Metro, if it doesn't idle up, drops over 400. The old Datsun B210 (120Y to Europeans) would actually stall sometimes when you engaged the AC.

Also, my fullsize spare steelie is probably smaller than some of your space savers. Small=awesomeawful

FTFY.

 

[narf]

So, I would imagine that certain locations for rental car facilities get loaded up with one way drivers meaning one location has too many cars. Surely there's a job where somebody ends up having to move cars between facilities. How does somebody get that job? Does UHaul deal with the same thing?

After Eyjafjallaj?kull many rental companies over here had offers up for one-way rentals to Spain and the likes for virtually no money to get rid of all the Spanish rentals that replaced the grounded aeroplanes :lol:

 

[Perc]

If your AC is off, the center of the pulley, where the clutch is located, will not spin. If the AC is running, the whole assembly will spin together. You can then experiment with modes to see when your compressor kicks on and off.

I realize I'm trying to out-Spectre the master here, but I'd just like to point out that some cars these days have clutchless AC systems. Instead of a clutch, there's a variable displacement compressor that regulates the amount of compression anywhere from 0 to whatever "max" is. I can still hear the strain on the engine change when I turn the AC on and off, but there's no clutch.

 

[Spectre]

I realize I'm trying to out-Spectre the master here, but I'd just like to point out that some cars these days have clutchless AC systems. Instead of a clutch, there's a variable displacement compressor that regulates the amount of compression anywhere from 0 to whatever "max" is. I can still hear the strain on the engine change when I turn the AC on and off, but there's no clutch.

Since when does a 2001 Mercury Cougar V6 (which is the car of the poster I was responding to) have a variable displacement compressor? If memory serves, it's going to be an FS-10 like the one I just swapped out on my truck and it definitely has a clutch. I just can't remember where they put it on the Cougar V6. Edit: And I'd have to actually care about the Cougar to want to go look it up and refresh my memory.

 

[public]

It amazes me how instead of conversation we mere mortals receive condescending nuggets of trivia delivered in a belittling fashion from somewhere high above. But that's hardly an issue, let's keep pandering to the master of know-how and perhaps receive a weapon photo or two for our trouble.

 

[93Flareside]

Random Thoughts... [Automotive Edition]

It amazes me how instead of conversation we mere mortals receive condescending nuggets of trivia delivered in a belittling fashion from somewhere high above. But that's hardly an issue, let's keep pandering to the master of know-how and perhaps receive a weapon photo or two for our trouble.

This is why I try avoid asking car questions on this forum. Obviously everyone of us except Spectre are incompetent tards.

He has good information but, it always becomes a debate.

 

[public]

For example, I hate how Rick gets treated every time he opens his mouth. We have actual idiots on this forum and on IRC, but it's him who gets talked down like he's Private Pyle.

 

[Spectre]

For example, I hate how Rick gets treated every time he opens his mouth. We have actual idiots on this forum and on IRC, but it's him who gets talked down like he's Private Pyle.

See British/Columbian's signature just upthread for just why that is. Many people tried being nice and we got nothing but paeans to Saturn for it.