My A/C is warm at idle and speeds below 40. After about 20min on the highway it will blow colder air. The vent temp on the A/C is about 70 give or take. At highway speeds it will eventually get down to 40ish in the morning/evening, but in the heat of the day it is lucky to go below 60. And that temp is about the same at the front or rear vents. Here is what I've done so far:
- Heater valve is working
- Blend door is working
- I just soaked the condenser with simple green, and hosed it out from the back side so it is all clean.
- I put a set of gauges on and the pressure is high, but it is not nice out. Ambiant temp was 92 with a 78 degree dewpoint, so stinking humid and the Ex was sitting in the sun. I was about 60psi low side and 330 high side.
- While watching the gauges I sprayed a fine spray over the condenser for about 2sec. That brought it down to about 250. Another 2 sec burst brought it down to 200.

If the front and rear vents are the same temp could it be the orifice tube? Seems like that would only affect the front. I thought about fan clutch, but at 30mph shouldn't there be enough airflow to cool it down? I also thought that maybe the front coil was dirty, but the rear is the same temp so that isn't it.

So, any ideas on what to check next? At this point I'm wondering is if it is overcharged? According to the shop manual the low side is ok, but high is way out.
http://www.motorcycleproducts.org/Ex...stem-tests.pdf
But again, I'm not testing in real great conditions with the current heat load and humidity. I've read alot of guys saying they get great cooling around 35psi low side so maybe I should try dropping my pressure. The only other thing the shop manual mentioned was possible water contamination.

I'm new to all this so let me know if I'm running down the wrong rabit trail!

 

I did this fix and now my A/C works great! SpringerPop's Compressor Clutch Air Gap

 

Got the same problem, gonna see if I can pick up the shims needed from the dealer this evening...I'll keep you all posted.

 

That is a nice write up! I don't think that is my problem though? Mine works, just not as cold as it should be. I'll check the gap anyway when I get home.

 

Ok, a little update:

I was thinking about how I tested the system and I thought of a problem. The shop manual said to set the fan on high, but nothing about the rear system. I had the rear system on high also. Testing with only the font it was 35/205, 85-90 degrees outside and very humid.

I figured the high humidity and heat load from a scortching hot engine bay were contributing to the 205 pressure. As soon as there was more air movement it would drop.(like when driving slowly, yes I drove with gauges sticking out of my hood) So I added 12oz of 134a. Brought me up to 36/205 and vent temps from 70 down to 60. So, I added another 12oz. Brought me to 37/205 and vent temps were about 40 - 41. In the time it took to put in the second can every window fogged up so badly on the outside that they started to drip...and I didn't have the rear system on. With the rear system on it warms up to about 50 now. I do know in the 6 months I've owned the Ex I've never felt the A/C this cold.

It seems like 24oz of 134a is a lot to add, I'll be monitoring the system to see how quickly I lose it. I did notice one pretty good dent where a rock hit the condenser, I may need to check that for a leak.

So, now I'm wondering a few things:
- Is it normal to add 24oz of refigerant and only see the pressure on the low side come up 2psi and high stay about the same?
- Should I add any more? Pressures are still in "spec" so I could.
- Am I a moron and missing something and shouldn't be adding refigerant? I feel a little dangerous with a set of gauges and some 134a. I'd like to be able to evacuate the system, weigh and recharge, but I don't have the equipment for that.

 

Have you put an aftermarket trans cooler in front of the AC condenser? Is your fan clutch working? There is an orfice where the gas expands through, that might be clogged. What is the outside temp. If you are in Arizona you might be doing as good as it is going to get.

Perry

 

Nope, no aftermarket trans cooler, fan clutch works, don't think it's the orifice because the rear is warm too.

It's been a busy couple days doing other stuff at home, but I think I'm getting it figured out. Like I said I'm don't know much about A/C, so I made a few mistakes testing.
- mistake #1, read the superduty part of the shop manual for testing
- mistake #2, didn't always run the a/c in the Ex at the same settings for testing. That caused varying test results.
- mistake #3 failed to realize how much residual heat and humidity will affect the high side pressure

For testing I'm now turning it down to 60, fan on max, recirc and rear on cold, max fan. The ambiant humidity is getting more reasonable again and the high side has dropped way down. Still about the same ambiant temps though, 88-93.

I've been talking with a friend that used to do HVAC work. He gave me a new perspective on how to setup your system. The pressure of the refrigerant directly relates to it's temp. The manifold gauge setups have temps on them too. If you are running 50 degree refrigerant on the low side(if I remember right that is around 40psi?) you won't have snowflakes coming from your vents. However, if you setup your system to have a 34 degree temp when it's 90 outside you'll likely frost over when it gets cooler because it will pull down below 34 degrees. My friend said he always looked at temps on the low side not PSI when setting up the system. PSI was there for reference, but temp was for "fine-tuning" the setup.

I haven't had much time to work on the Ex, but right now it is at about 48 degrees low side and blowing 55ish air out the vents.(ambiant air temp was 88) I was at about 55 degrees low side and rarely saw 60 vent temp, so it is better now. There is more room to tweak with that, but it's a start.

To show my ignorance I have one more question for you guys. I know new vehicles cycle the compressor(at least most do). Do they do that based on evaporator temp? So if you setup your system so it did drop below freezing at 70 degree ambiant temp, it would just cycle the compressor off untill it warmed up? Then I could set the temp closer to 40 from the compressor and it would cycle the compressor off if it dropped below freezing. I'm guessing that is how it works, but thought I'd ask the pro's.

 

Didn't need the shims after all, I pulled out the existing shim and now my A/C is ice cold, but the clutch will need to be replaced.

 

Glad it work for you!

 

Can't beat that for a free A/C fix!!

 

Rep points added!!