SergeyR1

The Texas heat is coming any day now and the A/C on my TSX 04 is giving me a sweaty headache:

- Even when it is set to 60deg the system is blowing warm air.

- Occasionally it blows really cold air for a minute or two and then it warms up again. I haven't been able to figure out if it's totally random or not.

- when I lower the temp setting the fan start blowing harder so I think the temperature sensor is okay

- I don't see a refrigerant leak. The little glass window on the line is full of clear liquid, there are no air bubbles, and I replaced a leaky A/C hose and filled the system not two years ago.

What can it be? Any other diagnostics I can do?

Sergey

TexasHonda

There are several possibilities. Following are most likely:

1) Clutch gap excessive - wear causes gap to increase until magnetic field will no close the clutch plate when energized. Fix is to remove clutch plate and remove shim underneath clutch plate to return gap to spec (0.020 +/- 0.006 inches). This is a common problem. Check that clutch coil is getting 12V when AC commanded and that clutch coil is not open (should be about 3-4 ohms). Fix seems easy but accessing compressor w/o discharging is challenging. If you're an experienced diy'r you should be fine.

2) Clutch coil is open circuit. Test w/ VOM. If open, new clutch necessary. Similar to 1) access w/o discharging is the challenge, but do-able. See youtube for videos.

3) AC relay intermittent. This is an easy one to fix. Replace relay. If you test for 12V and find nothing, this problem is likely.

There are other possibilities; AC pressure switch, thermostat, wiring, but above are most likely.

good luck

SergeyR1

Excellent info! Thanks!

cphresh

if youve recently had freon added they may have over filled it. i had an issue that was similar. over filling the freon made the compressor go out as well as one of my fans stopped working. it was a headache especially in the houston heat smh. Had a mechanic buddy help me fix it all tho so it wasnt too pricey.

TexasHonda

Any progress?

good luck

SergeyR1

I didn't want to celebrate too soon so I decided to drive for 3 days and wait for A/C to act up again. And nothing but cold air!

I decided to replace the relay before doing any other diagnostics because it was the easiest option. Amazingly it was just the relay! $5.69 and the problem is fixed.

To add it to the symptoms: A/C would blow hot air then cold then hot air every 5-10 minutes. Important: turning A/C off and then on again often would fix the problem for a few minutes. If you are getting the same problems replace the black relay in the middle first.

Thank you TexasHonda!

TexasHonda

Thanks for update. Sometimes you get a simple repair.

good luck

bradykp

how do you replace the relay? mind posting a brief description? i just started a thread (didn't search) on the same topic and then found yours - i'd like to try the relay myself and see if that fixes my 2006's issue.

bradykp

my wife has since updated me:

air isn't blowing. but, if she opens the sunroof - it starts to blow, but very lightly.

TexasHonda

No blower is likely. Slight movement w/ sunroof open is likely natural circulation and not blower motor driven.

Problem can be the transistor that controls blower motor or failed blower motor. Are you up to using a Volt-Ohm Meter to perform some tests?

good luck

bradykp

yeah, if you can describe what i need to do, i can manage to do it.

bradykp

oh and i took it for a ride tonight - it's no blowing at all. i played with the sunroof and i don't know what she's talking about lol

TexasHonda

Disconnect power transistor and measure resistance across terminals 3-4 (lower two terminals opposite side from retaining clip). It should be 1.4-1.5 kohms. If outside this range, replace power transistor.

If good suggest jumpering 12V to blower motor directly to check blower motor function.

A shop manual is highly recommended (automanualsource.com for $22).

good luck

bradykp

where do i found the power transistor though? i'm assuming the blower is under the glove box like here:

DIY- How to Fix, AC power transistor - Honda-Tech

TexasHonda

Following video for Accord should work for TSX.


good luck

bradykp

OK - i tried swapping the ac relay out and using one of the relays on the left, and it came on full blast. got all excited, thinking i just need new relay. swapped them back, it came on again, and then cut out in 10 seconds. cut the engine, and it made a click click noise.

so now, relays are all in original position - so i swap again - comes on, turns off. click click under the hood again.

i put them all back to original, but it doesn't seem to be the relay, does it?

bradykp

ok - a nice twist to the story. went back out, turned the car on, works 100%. took it for a spin about 2 miles, worked the entire time. wtf?!

TexasHonda

An intermittent relay might cause your symptoms however, since you swapped and got basically same results, this seems unlikley.

It's also possible it was something like a loose/weak connection of the blower relay which swapping fixed or temporarily fixed.

More likely either intermittent power transistor or weak brushes in the blower motor (causes intermittent blower action).

A good test of the blower motor is to thump the blower housing hard when blower isn't working. If blower promptly comes on, the worn brushes are the problem. A new blower is the fix.

good luck

bradykp

OK - today....turned on, worked for a bit, turned off. now she says it's not blowing at all when she took it out for lunch.

if it's the connection issue - how would that be fixed?

i'll take the cover off this weekend and thump the blower. i was gonna buy new relays (and just replace all 3 that are identical - probably not necessary but i figured might as well), but now i'm thinking it's either the power transistor or the blower motor (both of these are under the glove box - right?).

TexasHonda

I know blower is under the glove box and video shows PT inboard of blower. I'm assuming the TSX is same/similar, but shop manual diagrams don't make it clear.

Try thump test on blower housing. Easy and rules out PT and ID's blower as bad part.

good luck