A/C problem since front end wreck

[ltslimjim]

Some background: 2007 Honda Fit Sport with AT The sypmtom: A/C works great, it just seems to take 10 minutes into a drive; sometimes changing speeds/vent setting/to defrost can encourage it to kick on sooner, but once it turns on there isn't a problem and it works fine. If I restart the vehicle without it sitting for hours it tends to not take that time to kick back on but may or may not work again right away. Why would it do this? I was in a wreck last fall. Hit a deer and fixed it cheaper using a family friend for the labor; as the radiator support was bent slightly at the top (deer flipped into the hood and pulled the hood latch toward the engine several inches bending the radiator support), but the car drives fine and I was being quoted by pro shops to replace the radiator support (I understand they wouldn't want to warranty the work without ensuring it wouldn't be a problem later but we're talking an additional $1,500 b/c of Honda price on that piece to weld in). I digress, before the wreck the only symptom with A/C trouble was corrosion inside the passenger compartment fuse box causing the blower motor to not work or be intermittent/weaker. This came back and removing/replacing the fuse (which is still fine if not for slight discoloration on the prongs) fixed the blower motor issue itself. The delay in the A/C compressor actually engaging and working during drives happened this year though so it wasn't immediately following the collision and I'm not sure what to think. My first thought was I wondered if a freon leak created a low charge to the system. Is this what a low charge does? Seems electrical in nature to me; as if a relay or switch isn't engaging properly when first starting. Once it turns on, the compressor seems to work just fine. Any thoughts? Can't afford to go to a shop yet and the summer heat makes some drives after work brutal to start. Thanks! PS: Apparently, the rear hatch has a slight leak I haven't traced down, yet. So, there is at times ingress of water when it rains which collects into the spare tire area. I live in Atlanta. It's humid on top of this. EDIT: Could it be a problem with the expansion valve?

 

[Chris142]

Go get it properly evacuated and charged by a shop with a machine. Not some Yahoo with cans and see how it t does.

 

[ltslimjim]

Originally Posted by Chris142

Go get it properly evacuated and charged by a shop with a machine. Not some Yahoo with cans and see how it t does.

Well, I haven't had the system checked yet due to funds. I will have to find a pro and start digging. Just trying to ask about the symptom itself and trying to understand the process more. Seems like evaporator or expansion valve may be flaky from my amateur readings.

 

[CoolShirtDude]

First step would be to use a gauge set and check both the low and high pressure. A/C systems have a low pressure switch that will prevent the compressor from running in the event of a low charge or empty system. I suspect since this was in an front end accident the condenser is leaking. You really need gauges to diagnose an expansion valve. I recommend that you evacuate the system and see if it will hold a vacuum, if not you'll need to locate the leak.

 

[spasm3]

Originally Posted by Chris142

Go get it properly evacuated and charged by a shop with a machine. Not some Yahoo with cans .

 

[Darwin1138]

If the ac works without problems once engaged, you don't need to mess around with the gas or gauges. Your problem seem to me to be electrical in nature. Most probably a bad connection to earth because of the repair. Check the connections on the compressor, the condenser temperature sensor and the condenser pressure sensor. Look for loose connections or corrosion.If the connections are fine look for damaged or frayed wires from the accident. also if the clutch coil is grounded trough the compressor itself see that the bolts are properly torqued and that the threads are clean. And take another look around the fuse box for corrosion. If everything looks fine then maybe the Clutch coil is on its way out. You could change it without evacuating the system.

 

[StevieC]

Sounds like the expansion valve on the Firewall is the problem. I had a similar experience with my Dodge Journey before it was totaled. I don't think the accident has anything to do with it. This is easily diagnosed with a set of refrigerant gages by someone who is experienced. You can see for yourself on YouTube if you search for Expansion Valve diagnosis.

 

[Trav]

Originally Posted by Darwin1138

If the ac works without problems once engaged, you don't need to mess around with the gas or gauges. Your problem seem to me to be electrical in nature. Most probably a bad connection to earth because of the repair. Check the connections on the compressor, the condenser temperature sensor and the condenser pressure sensor. Look for loose connections or corrosion.If the connections are fine look for damaged or frayed wires from the accident. also if the clutch coil is grounded trough the compressor itself see that the bolts are properly torqued and that the threads are clean. And take another look around the fuse box for corrosion. If everything looks fine then maybe the Clutch coil is on its way out. You could change it without evacuating the system.

+1 ^This. If the A/C is getting cold or working normally when it does come on I doubt its in the actual system but more of an electrical issue. Easy enough to test, just check for power at the clutch with the A/C turned on, if there is none then you just pretty much eliminated the system and clutch. If power is there and the clutch is not engaged its probably a bad clutch. Honda is notorious for bad A/C relays especially the ones made by Omron, check the pins for corrosion and try another relay, there are quite a few the same in there so just pinch one of the ones not required for running the engine for a few minutes to try, if it works well go get another relay from the parts store. Bring your old one so they can go by the actual number not the application. If the relay is okay you might be dealing with a bad pressure switch or temp sensor if its used. A bad expansion valve or plugged orifice tube will usually have other symptoms when the system is in operation. Check the electrics first, that doesn't require the system to be opened and doesn't cost anything.

 

[mk378]

Were any A/C repairs done because of the crash? The first test to do is when it is not cooling, pull over leaving the engine running and the A/C on, and check under the hood: Is the compressor engaged? Is the suction line (from the evaporator to the compressor) cold? Another common problem is wear of the clutch plate and pulley making the gap too large. This causes intermittent engagement especially when it is hot under the hood. But you have to test some things or everyone is just guessing.

 

[FSully1]

Sounds like you have electrical issue.

 

[ltslimjim]

Thanks for the feedback. I agree with the approach of ruling out the electrical before opening up the system. Will update with results probably after labor day.

 

[StevieC]

If it sometimes takes 10 minutes to cool down this is most likely the Expansion valve and gauges will tell you in a hurry.

 

[Trav]

Interested to know what you find. When diagnosing issues rule nothing out but diagnose from the beginning not the end. Making sure the compressor is working and the clutch is okay is the correct starting point, gauges and all the rest of it are not helping if the compressor isn't running. An inexpensive Power Probe can be a big help with this sort of problem, and a must have tool if you do any amount of repairs, it allows you to inject power or ground from a common tool. One example.. https://www.amazon.com/Power-Probe-...05&sr=8-3&keywords=power+probe+3

 

[ltslimjim]

Update: Sorry for the delay everyone. I finally kicked my butt in gear and found out it was the relay. I swapped out the one exclusively labeled with an AC system logo for one only with a headlamp logo. Under the hood relay box. Immediately, I could turn the system on and off by demand. I swapped them back and the problem came back. I listened with fan setting on low and hood open; the bad relay would make a weird sound when it tried to engage. Uploading photo below. They appear identical other than the smaller number of 7271 for headlamp relay and 7291 for AC relay. A combo relay for AC and Cooling System(I suppose for the cooling fans??) was directly next to the one in question and it was also a 7291. Question. Headlights worked with "bad" AC relay. How soon do I need to get the bad one replaced if the headlights presently work with the known bad one?? Probably will drive to parts store tomorrow and get a new one regardless. Thanks everyone that helped!