civitas

I noticed today that turning on front defrost toggles AC on my recently acquired '97 EX. Googling frantically from a smart phone I discovered that this is normal (whew ). I also learned that you can toggle this off via dialing down fan / temp and then starting up with recycle / AC buttons held down.

What to do though? I don't like the idea that the AC compressor is going to fire up each time I need to blow off a bit of condensation. I get the physics. I'd still prefer to manually turn on AC to augment defog rather than being forced into it.

Is there a consensus on this point? Is it considered to be best to just leave the factory setting in place? Would deactivating auto-AC on defrost be likely to extend / shorten the service life on average of the AC unit?

I expect this issue has been addressed before, so thanks in advance for your patience. Advice, guidance, a link to a good run down on the topic would all be appreciated.

Thanks!

Former User

If you understand the physics, then you understand the engineer's design and intention. If you use the defrost setting to defog the windshield and windows, then why would you want it deactivated?

civitas

While your point is well taken, please note that the Engineer's design and intention is not quite as unambiguous as you suggest. Rather, the Engineer has indicated a preference and provided a choice: the ten second, no tools required method of deactivation is also part of the design and intention.

The issue runs across several makes and models that use the same hybrid vent / AC tactic and supply identically the same deactivation method. Users appreciate the physics of bringing AC into play, and fear increased AC maintenance and repair costs, particularly on 18 year old AC units getting toggled on and off more often than is necessary.

I am especially interested to be guided as to the known robustness, on average, of the AC units installed on Honda Civics for 1997 and thereabouts (say anything pre-millenial). If on the one hand they are reputed to be rock solid, rarely if ever requiring service, then I'll be inclined to give the default mode a chance, even though it goes against my grain. On the other hand, if it is considered routine to require AC unit repairs on pre-2000 Civics, then I'll be inclined to avail of the toggle supplied by the Engineer and nurse the AC unit.

Former User

I'm not sure yet whether this a troll post or a serious question. Regardless, fearing whether proper usage of my defrost function will break your A/C system makes no sense whatsoever in my opinion. It's like saying "I need to stop driving my car because I'm wearing it out". Let your car be a slave to you, not vice versa. You've got to pay to play man.

I have 97 and 00 Civics with the original stock A/C systems. I needed to add refrigerant (about 3/4 of a 12 oz can each) once in the entire time I've owned them. I live in Houston and use my A/C with wild abandon. Please stop obsessing and start focusing on important things in life.

tony_2018

Users fear ac maint....wtf... **** that I'm glad I did maintenance on mine because its gonna help me make it through the summer. Tx heat ain't no joke but if you add the humidity, aka New Orleans, you better pray you make it through with it working as it should.

civitas

That wasn't a question. It was a report of user concerns.

Please note that proper usage of the defrost function includes linkage of the AC unit to defrost [default] or non-linkage of the AC unit [optional]. The sense of choosing the optional method pertains to to such things as prudent cost management; context driven performance choice (defog without AC works fine in some climates or conditions); optimization of vehicle power; optimization of fuel economy; and aesthetic preference to list just a few of the factors that influence those who choose the optional AC disabled mode.

What you have called an "obsession" is a technical query moderately posed in an appropriate technical forum.

As regards your report, thank you for this reply to my question.

HondaPartsHero

I think you're over thinking something very simple. Just leave it. I've owned over 10 Honda's and used the AC and defrost day in and day out and have never had to replace a compressor. Not saying it can't happen but I've had most of these for well over 200K miles. The only things I've really ever had fail were refrigerant lines and o rings.

Former User

This^ type of response obsessing over a non-issue is so farfetched that it easily could come from an accomplished internet troll.

civitas

Guys, knock it off with the trollery nonsense and stay on topic.

The topic is the ins and outs of deactivating the AC tie in to defrost mode on a ’97 Honda Civic EX. Again, the manufacturer supplies a 10 second, no tools switch precisely because in their greater wisdom Honda Tech designers decided that there was room for both options.

Thank you for this report that you have run your AC units with “reckless abandon”, and have had to perform AC repairs on both of your Honda Civics.

Thank you for this report that you have had refrigerant lines and O rings fail on your AC units.

The take away I get is that you both consider the units to be robust enough to run hard without a thought. At the same time, all of your units have degraded or broken down and required repairs. To me that’s an ambiguous message. Fails when run hard, but not hard to repair if you're a mechanic.

The evidence I've seen so far sugests to me that deactivating the AC tie to the defroster, combined with mindful use of the AC unit, may be a good tactic to extend the service life of AC units in pre-millenial Honda Civics.

Former User

This thread has come to its logical conclusion.

toyomatt84

iTrader: (1)

I'm sorry civitas, but your haughty reporting doesn't help the case you're trying to make. RonJ was more then conclusive as to the unnecessary concern made towards the A/C system being involved during the act of defrosting. And, although it's a fair request, the information provided should be more then sufficient for you to make your own decision as to whether or not you want the A/C system activated or not. Whining about how a user provided information is a bit childish, and truly unnecessary on a technical board. If you're offended by his responses, you may want to grow a bit thicker skin for internet-based forums. We've got a far lighter atmosphere then some out there.