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1990 Honda Civic A/C intermittent issue


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bach
Novice
bach profile image

May 29, 2007, 2:49 PM

Post #1 of 15 (5233 views)
1990 Honda Civic A/C intermittent issue Sign In

The A/C in my 1990 Honda Civic LX sedan has been driving me crazy. It seems like every morning it works great, but once I turn off the car, it may or may not work again that day when I fire up the car again. Most of the time it won't work if the car has been sitting a while after that first ride. Occasionally on other drives of the day it will work again for a while, but then stop working again. One time I took off for the beach in the morning for a 3 hour drive and it worked the entire way. The stops along the way were brief. The A/C indicator is always on.

I looked at the schematic and made some measurements. According to the schematic, coming off of the compressor clutch relay is a red wire that goes to the compressor. Within the compressor is a thermal protector. There is a connection along the red wire where you can disconnect the line coming from the compressor clutch relay from the line that continues onto the compressor. I measured the voltage on the line coming off of the relay and it measures around 12.5 Volts when the A/C button is pressed in (A/C on) and no voltage when the button is out (A/C off). I measured that same spot when my A/C was working and blowing cold air (compressor clutch engaged) and not working (A/C button pressed in, but compressor clutch not engaged, so warm air blows) and it always reads 12.5 Volts so the relay seems to working (at least relative to the A/C button being pressed in). Also according to the schematic, the compressor runs because of the voltage supplied by the red wire and the other end of the compressor being at ground. The only thing between the red wire and the compressor clutch is the thermal protector, which basically looks like a simple switch (closed most of the time, but open when there is a thermal issue so that the compressor is protected). When I measured the voltage disconnected red wire that goes to the compressor, it appears to be at or near ground. If the thermal protector was preventing the compressor clutch from engaging, I would expect it to be open and to see no voltage (basically just a red wire disconnected at both ends).

The schematic doesn't show the ECU directly wired to the compressor. It assume that if the pressure switch or thermostat switch in line with the A/C switch pop open due to some problem, then the ECU would cause the compressor clutch relay to open to protect the compressor. Am I wrong with that assumption? How else would the compressor be protected? If there is another way that the compressor is disengaged, that would explain why the relay is still compressor (12.5 Volts shown on the red wire), but the compressor is not running.

Any ideas would be very much appreciated as it has gotten hot in the Baltimore area. :-(

Thanks.


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

May 29, 2007, 3:40 PM

Post #2 of 15 (5230 views)
Re: 1990 Honda Civic A/C intermittent issue Sign In

Relax! Your working too hard at this. This is probably a clutch gap that is too wide to engage and aggrevated by heat.

To test: Catch is when not working and even with engine off but in run position tap on the outer hub of the compressor's clutch. If it snaps in it's engaged. It should do that by itself with A/C request but the gap gets wider in time and use and it can't. You can try that trick with the engine on an look at the outer hub not turning with A/C and tap it then and it will stay on for a while for you. Carefull of moving parts and tap with something other than your hand as when it kicks on it will spin.

Betcha that's it. You can adjust that gap if too large to be closer. Usually just removing the outer hub by the center nut, pull out hub, and remove a spacer shim (like a little washer) and put it back on. Check the gap with a really high tech folded business card which should now be snug in that gap. It can't be left so tight that it rubs when off.

That nut can be hard to get at so try going thru the wheel well if this seems like the problem and hold the outer hub gently without hurting it with whatever will hold it to loosen that nut. Hub should just pull off. No need to mess with refrigerant or even take the belt off. Any splines may be off set so that it only goes on one way so mark it for right position.

Hit back if that doesn't seem to be the problem and we can look into it more,

T



bach
Novice
bach profile image

May 29, 2007, 6:52 PM

Post #3 of 15 (5228 views)
Re: 1990 Honda Civic A/C intermittent issue Sign In

Relax! Your working too hard at this. lol Tom - I know both my wife and my close friend agree completely with that statement and will be very glad when they don't have to hear about my intermittent A/C problem any longer. I definitely have felt like I've been working too hard on this without any significant progress, and sure felt that way today when I was sweating like a pig during my lunch hour.

Thanks for the idea about checking the clutch gap. I hope you are right. I'll let you know how it goes.

Mark


bach
Novice
bach profile image

May 30, 2007, 12:32 AM

Post #4 of 15 (5222 views)
Re: 1990 Honda Civic A/C intermittent issue Sign In

Hey Tom,

You are the Man! Tapping on the outer hub of the compressor's clutch engaged the clutch. It usually took a bunch of taps as it was difficult with the limited spacing to get good taps on the hub, but eventually it kicked on. And thanks for the tip about not using my hand!

It will definitely be difficult getting to the center nut from above to remove the outer hub, so going through the wheel well seems to be the best idea. There's only one problem and I hate to admit it, but how do I go through the wheel well? Looking at the wheel well on the driver's side with the tire/wheel still on, it looks mostly like a solid piece. I have experience with different parts of my car, but this isn't one of them. Some more help will definitely be appreciated again.

Getting back to what I accomplished tonight, thanks for helping me get past a major hurdle and retaining whatever sanity I still had left by getting to the root of my A/C problem. Now I can relax somewhat. Full relaxation will depend on what other info you give me concerning accessing the outer hub through the wheel well :-)

Mark


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

May 30, 2007, 5:22 AM

Post #5 of 15 (5219 views)
Re: 1990 Honda Civic A/C intermittent issue Sign In

Cool Beans from Boston!! You've found the problem thanks to kitty -- she's the technician, I just do the typing. Hey, if you have some sanity left would you please share it. Mine left with the last of the Mohicans!

This issue now is how to get at it: Look at that hub as it faces the inner fender. It probably faces plastic inner fender which can be moved. Keep in mind that the head of the clutch needs room to slide out and even with the nut removed my not have room. Inner fender should move with just plastic clips and things that will probably break but they are available in the hair replacement isle at your local parts store.

You may need to move or remove compressor. Just tilting it may work. If it has to come out you will need to have refrigerant recovered, fix the gap, replace any lost oil, and have it vacuumed out and recharged by weight specified. That could make farming out the job the most cost effective as the equipment for a one time job would never be worth it.

Wish I had a Civic to look at but don't right now. Hit back with what you find. Say where you are from and I might know of someone near you if you need a shop to do this,

T



bach
Novice
bach profile image

May 30, 2007, 8:52 AM

Post #6 of 15 (5214 views)
Re: 1990 Honda Civic A/C intermittent issue Sign In

Tom,

Kitty is one tremendous tech. One great cat deserves a friend, so check out my new pic. It's one of my cats. His name is Target because we found him as a stray near a Target store many years ago.

I wish I could spare some of my sanity, but I'm holding on to my sanity by a thread. Sorry I couldn't help you, my Mohican friend.

It's not even May and the Red Sox are running away with the division. The Yankees must be hating life for spending $18 million for Roger Clemens to play for at most 65% of the season, only to find themselves in last place in the division, 14.5 games out of first place, and 8 games or so out of the wild card spot before Clemens has even thrown a pitch. As for the Baltimore Orioles, I could care less. I live in Columbia, Maryland, in Howard County, not far from Baltimore city. I used to be a huge Orioles fan and partial season ticket holder, but our lousy, pompous owner's meddling over the years and 10 years of losing just killed my spirit. It also didn't help the Orioles that we got a football team back in 1996. The Ravens organization seems to do almost everything correctly while the Orioles organization is just the opposite.

I'll let you know how the compressor fix goes.

Do you know of anyone near me that has a shop if I need help? I work near BWI airport.

Catch you later, Tom.

Mark


Tom Greenleaf
Ultimate Carjunky / Moderator
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May 30, 2007, 12:16 PM

Post #7 of 15 (5207 views)
Re: 1990 Honda Civic A/C intermittent issue Sign In

Hi again,

Had in laws in the Charlstown retirement community near Catonsville and their son-in-law works as a mechanic in Brandywine but he's only marginal as a mechanic and would know nothing about A/C so forget that. The last in law passed away in 2004 so any contact for right there is too late now.

I've been around this country a lot in younger years. All but 3 states. Been to HI and AK which were tough to knock off my list. Did Mexico for a day, and about half the Provinces of Canada.

Let us know how you make out with the Civic,

Kitty is waiting,

T



bach
Novice
bach profile image

May 30, 2007, 3:53 PM

Post #8 of 15 (5202 views)
Re: 1990 Honda Civic A/C intermittent issue Sign In

Tom,

No big deal about not having a mechanic to refer me too. I've come this far, so I'd like to see this all the way through without paying a mechanic anyway.

Do you know anything about transmissions? If so, check out this post of mine - http://autoforums.carjunky.com/...forum.cgi?post=13834.

I'll be in touch,

Mark


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

May 30, 2007, 3:59 PM

Post #9 of 15 (5201 views)
Re: 1990 Honda Civic A/C intermittent issue Sign In

Transmissions? Yes but not a specialty. I'll check that out,

T



bach
Novice
bach profile image

Jun 4, 2007, 11:28 AM

Post #10 of 15 (5183 views)
Re: 1990 Honda Civic A/C intermittent issue Sign In

Hi Tom,

Some weather and sickness has slowed me down, but here's where I stand. I'm at the point where I'm about to tackle the nut on that holds on the hub. I've definitely had a learning curve on this job. First, there is no access to the compressor through the wheel well, since the wheel well is solid. Secondly, there is virtually no room between the hub and the wheel well, so the compressor had to move away from the wheel well.

I removed 2 bolts from the power steering pump, removed it's belt, and swung the power steering pump out of the way without disconnecting the fluid lines. I then disconnected the idler pulley that applies tension on the compressor belt and removed the belt. Next, I loosened the 4 bolts holding down the compressor to loosen it, but I needed more room to move it because of the freon lines. I had to remove both fans (radiator and compressor) and an engine cover (the cover the oil dipstick goes through). Finally I had room to swing the compressor up enough to get a good look at the hub. I rented a compressor clutch holding tool, but it didn't seem to fit properly. That's about when I started feeling lousy. I'm planning on picking up where I left off today, weather pending, and a friend of mine will help me. I have a set of bent needle nose pliers that I think can hold the hub while loosing the nut, if one person holds the hub and another turns the nut. How big, in diameter and thickness, are the shims? The spacing I saw didn't look like much, kind of like your description of a bent business card. Are the shims visible before removing the nut? Maybe I'm looking at things wrong and everything will make sense once the hub is off. I bent a lot of fins in my radiator removing fans and working on nuts that haven't been loosened in 17 years. I hope I don't need to replace it.

Give me some encouragement now that I've gotten this far,

Mark


Tom Greenleaf
Ultimate Carjunky / Moderator
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Jun 4, 2007, 7:32 PM

Post #11 of 15 (5177 views)
Re: 1990 Honda Civic A/C intermittent issue Sign In

Shims are quite thin. There may only be one to take out. Air tools can remove the center nut without having to hold the outer hub with more than a rag sometimes.

Easy on your radiator!,

T



bach
Novice
bach profile image

Jun 4, 2007, 8:30 PM

Post #12 of 15 (5175 views)
Re: 1990 Honda Civic A/C intermittent issue Sign In

Tom,

This has been the night from hell. My friend came over to give me a hand and we couldn't get the center nut loose. The nut eventually stripped so we went to Sears to buy a socket that goes over a stripped nut, which actually grabbed the nut pretty well, but still no luck. We even heated the nut with a propane torch and it just didn't budge! It's amazing that an 8mm nut (I think it's actually a bolt) can be on that strong. I'll keep you posted. I don't have an air tool or compressor.

Mark


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Jun 5, 2007, 3:33 AM

Post #13 of 15 (5174 views)
Re: 1990 Honda Civic A/C intermittent issue Sign In

Go easy guy. I don't know it but this could be reverse threaded! Watch out for that with anything that turns car and home things. Fans do that the most. This shouldn't be this hard and if that thing breaks you probably will need a whole compressor to fix this!!!! That will not just cost for the compressor but then it will have to get a vac and charge and that's ok but the cost of the equipment gets up there. Some can be rented but let's not go there about this.

Easy on using heat as there's a rubber shaft seal not far away and the bearing of the clutch itself,

T



(This post was edited by Tom Greenleaf on Jun 5, 2007, 4:34 AM)


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Jun 6, 2007, 7:24 AM

Post #14 of 15 (5166 views)
Re: 1990 Honda Civic A/C intermittent issue Sign In

Just perused two Civic from early 90s to check out exactly what you are dealing with. Damn that's tight working if it's like the ones I looked at. Yes there's no getting at that thru the wheel well -- all body metal and room to even angle the compressor is tight. No wonder you bent some fins on the radiator.

While working at and with a shop I've dealt with for years the consensus was the clutch is regular threads but anything is possible. By far most are regular and it seemed that direction of rotation would be consistant with that. Hope you haven't busted too many knuckles getting this done,

T



bach
Novice
bach profile image

Jul 23, 2007, 1:28 PM

Post #15 of 15 (5080 views)
Re: 1990 Honda Civic A/C intermittent issue Sign In

Hi Tom,

I was just writing a novel to you when I lost all that I was typing. An application at work launched into the same window as this one and when I hit back my text was gone. Doh! I don't have the strength to go through it again at the moment, but I wanted to get back to you anyway.

First let me apologize for not getting back to you sooner.

After 2 to 3 weeks of hell, I got my A/C working about a month ago. In the end, I removed the one and only spacer under the clutch and bonded the clutch onto the compressor shaft using JB Weld because because I couldn't get the bolt out of the compressor shaft cleanly after shearing off the bolt head. I'll tell you the entire story another time, but in the end my A/C is working like a champ again each and every time.

Thanks so much for telling me why it was acting intermittent. You were right on the nose.

Mark


(This post was edited by bach on Jul 23, 2007, 1:29 PM)






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