Rep Power: 0

Hey folks,

Car is an '02 Acura 1.7EL.

My A/C has been acting weird of late. The fans, compressor, etc all appear to work properly, but the air coming out of the vents is intermittently humid and outside temp / dry and cold.

A Honda parts (all techs had gone home for the day) suggested a temp sensor which trips the compressor on/off and mentioned something about something on the compressor itself, but he wasn't very clear.

Can anyone shed some light as to what might be going on here? Other than my DRL issue (now fixed), I haven't had any electrical issues with the car.

Thanks!

 
Rep Power: 812

when you listen to the car from outside, how often does the compressor kick on and off? it should not stay on all the time, and ive noticed that when it turns off, the air gets humid and hot but thats a normal problem.

 
Rep Power: 0

It does turn on and off (I've always heard a thin squeal when it kicks on). It still does that, but it's never blown hot/humid before. It's worse on very hot days (almost never kicks on) and not so bad on cooler days (I actually get AC most of the time).

I asked at the dealer and they told me it's likely a faulty thermal overload sensor on the compressor that's kicking it off (and keeping it off). They want $80 for the sensor and 4 hours of labour ($400) to change it out.

I had a look in the bay today and I can see the compressor way down at the bottom.. looks very inaccessible. Has anyone changed one of these sensors before and wouldn't mind sharing some thoughts? Any tips on MacGyvering a solution (ie: bypass the sensor) so I can have AC?

 
Rep Power: 812

i would get a second opinion. thats very expensive for a sensor and that may not even fix it. you say the compressor turns on and off so how could it be the sensor? sounds more like a receiver/dryer problem if the air is humid.

 
Rep Power: 812

i would get a second opinion. thats very expensive for a sensor and that may not even fix it. you say the compressor turns on and off so how could it be the sensor? sounds more like a receiver/dryer problem if the air is humid.

 
Rep Power: 291

Mine did this too. I go to school in Orange County so the AC would usually work. When I visit my parents in bako where its hot the AC would not always work. Does your car have times where it idles a bit high?

If your willing to troubleshoot this yourself I can write down what needs to be checked. Its fairly straight forward and all you need is a set of feeler gauges, a multimeter, and a jumper wire.

 
Rep Power: 0

By any chance does your thermostat read over heating at times and the car is actually not overheating?

 
Rep Power: 0

I thought it was way pricey too.

Only reason I suspect it's the sensor is because this particular one is supposed to shut off the compressor when it detects (or thinks it does anyway) an overheating situation in the compressor. Service tech at the dealer told me that, since it's 7 yrs old, it's probably corroded and shot (ice, snow and salt here in the winter, coupled with [in his words], the corrosive reaction between the copper clad sensor and the metal coating on the compressor), leading to it failing. I also suspect it since the system works when the ambient temp is cool and doesn't work when it's hot.

Why would the receiver/dryer cause alternate cool/dry and hot/humid air? If the compressor still worked, wouldn't the air at least be cool (even if humid)?

Yeah, it does idle high at times. Not often, but sometimes. Also seems to take a bit to rev down when shifting (ie: say from 4k, it hesitates for a moment when I press the clutch in and take my foot off the gas, then slowly drops down). I've normally associated this with an air intake problem, but the filter is fine.

Sure, would be interested in seeing your checklist and giving it a shot.

No, never. Once warmed up, it always reads at just under half. Only saw it go higher once when I was touring around Delaware on a stinky hot day.

 
Rep Power: 0

This is exactly what my car does. I was thinking it was the switch on the dryer that detects pressure, but I didn't know about the thermal overload sensor. That makes more sense because it almost never works when it's very hot out. I wonder if the big crack in my exhaust manifold is putting too much heat into the engine bay.

BTW, it's much easier to access the compressor if you take out the inner fender splash shield. If you know where the sensor is you could probably change it yourself. I'll have to look into that.

I would be very interested in this too.

 
Rep Power: 291

When it idles high can you turn the AC off to make it idle normally?

First off, get a set of feeler guages and measure the space in the AC clutch. If it's too big you'll need to pull the clutch plate off and remove a spacer. I'll get the exact numbers for you tomorrow. Access the compressor from the wheel well.

 
Rep Power: 0

I was browsing reddawnman's Timing Belt DIY and cross-referencing with the FSM. It looks to me that, even though I could access the compressor pulley via the wheel well, accessing the sensor on top may be next to impossible unless I remove the PS pump and alternator. Check out these pics (shamelessly stolen from the above mentioned DIY... props to reddawnman).

The compressor shown from the wheel well... still appears hostile to working on it's top:



Ignore the red mark ups.. those are reddawnman's. My markups are the light blue circle indicating the wiring, sensor and clamp on top of the compressor and the light blue arrow pointing at the sensor itself.



Definately a Honda "make work" project for otherwise under-worked service techs.

 
Rep Power: 0

So that's where the sensor is? I guess it would be easier to work on that from the top, but I was just looking at those wires the other day, and I didn't have any parts taken off. I'm not positive, but I'm pretty sure I could've worked on that without removing the P/S, and alt.. It might not be fun, but I think possible.

I just looked that sensor up on Majestic and it's $47.59 there.

 
Rep Power: 291

I pulled my alternator and power steering pump to get at that sensor. The test for the sensor is to check continuity. There should be continuity if its less than like 200 degrees f outside.

 
Rep Power: 0

Thanks, I'll check it out tomorrow. I wonder if, even if the sensor's fine , if it's getting tripped because I have a crack in my exhaust manifold, so there's probably a lot of extra heat blowing around in there? 'Cause if I turn the air off for a few, then back on it works for a little bit. Guess I'll find out when I replace it with a header next weekend.

 
Rep Power: 0

Hey folks,

Long time since this thread was updated, but a couple of weeks ago, I finally got around to replacing the sensor. It was a bear of a job as I suspected it would be since there's not a long of room for maneouvering in there. Took me 5hrs to do the job, most of which was disassembly (stuck bolts, sorting out how stuff came apart and finally, getting that stuff apart), which, if the dealer charges 4, I guess isn't so bad.

But, I don't think it's fixed the problem. It hasn't been really hot enough to use the AC but I'd turned it on once last week and it was blowing nice and cold for a while, then it must have kicked off since the air warmed up again.

What else can I check?

 
Rep Power: 0

Bump.

Anyone have any thoughts on this? It was pretty hot out today and the problem has definately not been fixed.. AC is still intermittently hot/cold.

 
Rep Power: 0

I am having the same issue. a mechanic friend said might be the TVX valve, but that is inside the dash and a bitch to get to.