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Another A/C blowing hot air problem

32K views 8 replies 7 participants last post by  CaymanDjay 
#1 ·
I have an 2003 EX (76k miles) with Climate Control System. My problem is a little different from the one that was described in TMAC5's thread. When I set auto and the knob to the maximum cold position (60) , A/C actually blows
a little cold air but not that cold and fans also turns to maximum speed. The rear part exhibits the similar behavior. But when the knob was positioned at 67 or above, it blows hot air.

I don't know much about A/C and I am learning. I hope I can get some tips from your more experienced folks in this forum.
Thanks.
 
#3 ·
Thanks, Marshall2.

I read that thread before. But the fan in my car still responds to the fan speed knob, and it is not like it only runs when the fan speed knob is set to the highest.

But I will do a self diagnosis test
tonight as Williams Wiles suggested to see what code comes up.
 
#4 ·
OK, I had this issue come up on my wife's 2001 Ody this weekend. A local (not a Honda dealer) shop checked out the A/C system and told us compressor and condensor were good, freon was good, so they surmised it must be a bad "control head". Charged us $170.00 for diagnosis, then told us they'd have to order the control head--said it would be another $700.00 for part with labor. I was skeptical because the control head is basically a bunch of switches and they were all lighting up and displaying properly. Also was skeptical about how they were saying was very complicated to replace the control head due to lots of connectors that have to be "just so". I replaced burned out bulbs in my control head last year and it's pretty easy--take off the dash in about 15 minutes (a la clock light replacement) and swap out the bulbs into the back of the control head. And each connector only fits in it's proper receptacle, so you can't screw that up. Anyway...

Did some research on the net, was happy to find a video clip with the same specific symptoms listed:
1) A/C suddenly went out--one minute was blowing cold air, the next totally was not.
2) Fan doesn't blow at all unless turned on full speed; then it blows hot air.

Turns out it was a bad heater blower transistor. The part cost me $65.00 at the Honda dealer and took 30 minutes to install. I had to be a contortionist; it's way up under the passenger side dash near the outside corner. It's held in place by three 8mm hex screws.

Here is the video link:

There is a second video--if you have time and a soldering iron, you could take the old transistor assembly out, replace just the transistor (74 cents from www.digikey.com), apply more thermal paste and put back together. The "assembly" is just a heat sink to dissipate heat from the transistor. But I didn't have time to wait on that to come in the mail, so I spent $65 at the Honda dealer for the entire assembly today instead. Still way better than $700.00.

Honda part # 79330-S84-A41 (blower motor transistor assembly)

Best part of the story--my wife went back to the car shop, had the tech sit in her van blowing nice cold air, and after a minute, he excused himself to speak to the manager. A few minutes later, manager came out, told us they appreciate our business and want to keep us as a customer--so they refunded yesterday's $170.00 charge. I'm very appreciative that they did that! :D
 
#5 ·
Also, I had read that if you start the car, run the A/C and press the A/C and OFF buttons simultaneously and hold them down for up to a minute, that it will give a diagnostic code. Supposedly the display alternates between "88" and a letter code A through N, with N being a bad blower motor transistor. I tried it but just got the "88", no letter code, yet my transistor was bad and replacing it did solve the problem.
 
#7 · (Edited)
Similar problem on our 2000 model, almost 200K miles. AC would only cool when rear blower was on, and rear blower would only work on high speed. Needless to say, sort of a noisy ride! After searching on-line, and finding Odyclub, found out about blower motor resistors. Rear blower motor resistor, $39 + change through NAPA auto parts. Replaced it today, and now I have all speeds on the rear blower, and air is cooler coming out front vents as well.

Thank you, all you Odyclub members!

PS -- The Check Engine light had been illuminated for a couple of years, showing O2 sensor, and catalytic converter problems. After replacing blower motor resistor, CEL has gone off! Any possible connection, or shear coincidence? I'll update in a couple of days as to status of CEL!
 
#8 ·
It sounds to me like your blend door is not working properly. What the door does is adjust how much cold and warm air enters the ducts and therefor the cabin. To check have some one turn the temperature control knob from max cold position to max hot position while you are listening by the blower motor under the passenger side dash. You can turn the fan to low while you do this so you can better listen for the sound of a motor or door moving/closing. If you do not hear anything it is probable that the door is no longer working.
 
#9 ·
My AC went out suddenly on my 2003 Honda Ody - that afternoon it was freezing cold, then later in evening it was blowing warm air and didnt work after that except warm air. Was not a slow decline of cold air as many suggested low freon would do.
My trouble shooting included;

1) went to Autozone and bought a gauge that showed I had full freon in system and my blowers worked on all levels so not a transistor issue.

2) found the in- cabin filter (behind glove compartment) and it was disgustingly dirty, probably never been changed from looks of it (google how to replace this cuz can be tricky). That made air blow a little better but after 10 minutes was warm again

3) My pipes that carry the freon to the ac unit never felt cold to the touch ever even though gauge showed full freon.


Finally took it to Corey's Auto Service in Cumming, Ga and told Bruce that if it was my ac clutch or condensor, I couldn't afford to fix. First thing out of his mouth is that it is rare to replace a condenser unless faulty from factory in any Honda vehicle. He said however a LOT of other service garages will sell you a condensor replacement service.

Problem: i had Zero Freon in car. There were 3 areas in system where there were leaks on seals, one an O ring that was corroded, a cap where I put gauge on that was never put back on (from someone else that worked on ac before) and one other seal that over time the rubber just corrodes and the freon leaks out.
Gauge I bought at autozone was either a cheap gauge ($12.99) one or faulty and didn't register properly or air pressure built up in system gave a false full gauge of freon. Service mechanic said to never attempt to put your own freon in because you could ruin your system and all new pipes have to be installed. A saturn came in with same problem he said but they did put their own freon in and now their repair turned into a $1200 repair due to putting in freon when the system needed to be flushed first.


Cost of Repair - $250
Return of gauge, freon can and can of seal to fix seals for products to self-fix to Autozone
- Credit $86
Lesson - just take it in to a small garage that doesnt charge to look at it quickly and get a system AC check rather than self- diagnose. I could have screwed up my whole system.
 
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