A/C hot, no condenser fans or compressor 99E300

1753 Views 26 Replies 4 Participants Last post by 55Benz, Aug 3, 2017

55Benz

Discussion Starter · May 20, 2017

Hi Everyone. Last week while driving A/c air suddenly got hot. I purchase refrigerant and followed the instructions on resetting after the ec illuminated.
I hastily reset before writing down the code. Compressor come on but has occasionally for periods of less than a minute. I've tried to quickly add refrigerant while it's on with no success. Also according to my gauge the pressure on the low side quickly climbs when I try to add 134. This could be due to reading a value after the compressor has stopped running. Maybe? The pressure on low side according to my gauge was around 50psi. I let some gas out of the valve to lower it. I reduced it to about 10 psi. tried again to add when comp. briefly came on but no luck. Compressor only seems to come on when the car has not been running for 2 or more hours and I could get it or the aux fans to come on at all today. Fans turn freely by hand with no noted roughness. Fuses are all good in the engine compartment. I've run the diagnostics and will list their values below. Also I've been driving the car hoping the original fault will reappear but it has not and the ec light has not returned. Sorry I posted extra values. Thanks in advance for any help. It's hot here in Wilmington NC!
1 - 82
2 -78
3 -87
4 -87
5 -134
6 -94
7 -03
8 -82
9 -27
10-2.3
11-1.5
12-4.3
20-3.2
21-32
22-00
23-32
24-11.6
40-164
41-85
42-08
43-136

Save

21 - 27 of 27 Posts

55Benz

Discussion Starter · #21 · May 25, 2017

Update! Outside tonight shining flashlight at compressor to confirm turning (it was) there is a black greasy ring around the frontmost part of the compressor. In front of the pulley I suppose I would call it the clutch hub? The part that doesn't spin when the compressor isn't running. I shined my light straight down, and also saw what looked like a thin greasy string of like material on the front engine splash pan. Bad/disintegrated clutch? I'm sure it's not a good thing. Hmmm, so would that be the compressor appeared to be engaged and the disc-fiber material seized to the nose piece giving the illusion that the compressor itself was spinning. I guess I'm trying to menatally discern if the compressor may be okay and only the clutch bad. What's next? Remove the clutch and investigate further?

Save

mrboca

· #22 · May 25, 2017

#7 is the high side pressure which seems to be lower than your low side pressure

.

There is a hex nut in the hub, and when you run the a/c with EC not lit, the hub should turn. when you press the EC to turn the compressor off, the hub should stop spinning.

It is possible that your compressor is actually turning but set to kind of freewheeling (minimum piston compression), so the compressor is not compressing. If this is the case, maybe you have too much refrigerant, or the compressor control valve is bad or both.

Recently someone else had a similar warm air problem, he let some refrigerant out, and the system started cooling.

But the first thing is to make sure that compressor is turning when it is supposed to.

Save

55Benz

Discussion Starter · #23 · May 25, 2017

Hi,
It's definitely turning but with flashlight I'm noting greasy debris along the hub. Originally it wasn't turning. Then when I rigged the numbers on the control unit it's been turning whenever ac is on and ec is off. Recently even though the clutch hub is turning it doesn't seem to be under a load. I'm going to order a clutch and then tear it down. If I get into it and see more problems I suppose I'll send the clutch back and get a compressor and dryer and fresh o-rings. I hope I don't have to open the system though. I'm guessing part of the electric control to the clutch got damaged and prevented the fault code from returning. Are there any sensors or any other parts I should also replace with the clutch? (if that's all that needs replacing)
Thanks for all of your valuable info.

Save

mrboca

· #24 · May 25, 2017

If the hub is turning, the clutch is doing its job. It is just the swash plate in the compressor is in perpendicular position so the pistons are not compressing the refrigerant.

Check the attached link out for the Denso compressor. (it is in Russian, if you are using Chrome, right click on the page and press translate to english)

https://ukond.ru/schema/schema-compressora-7sb16c-denso/

You see the valve in the rectangle at the top ? That controls the compression ratio.

You also see how the clutch works. If the coil in the pulley is energized it will engage the hub which will turn the compressor shaft. If the swash plate is not at an angle, the 7 pistons will not move much. You may have a stuck
/ defective control valve

Save

55Benz

Discussion Starter · #25 · May 26, 2017

Hi,
I checked out the diagram and the control valve. That would make sense why it would hold pressure and not distribute it. Interesting I was expecting to see an eccentric shaft with veins around the perimeter. I messed with the car a few minutes ago. I let some of the pressure off of the low side. Still nothing. Initially compressor was turning. Then after letting pressure off (down to 35 psi.) it stopped shortly afterward. Not sure if that was related or not because the comp. had mostly stopped running days ago before I added the 16 value to trick it on.I jumped the high fans and the compressor came on also. I couldn't resist trying one last time to add refrigerant with the pressure down. It will take it when the pressure isn't too high but still no cooling. I was still perplexed about the black ring of goo around the front of the compressor clutch. I shut off the engine and without releasing belt tension I could easily turn the clutch housing in front of the pulley with my screwdriver. I could also jiggle it side to side at least an eight of an inch. That must be messed up. Possibly the the revolving plate (swash?) that controls the pistons stripped by the shaft? Not sure. I've looked at some package deals on rebuilds. I may take a gander at the local junk yard. They have a few compatible compressors in vehicles that just arrived I noted from their website: $35. I may gamble since I'm back in grad school and on a budget. No matter which route I'll replace the drier, easy to get to o-rings, and replace the oil with fresh. I'm sure more will be revealed. I don't want to take it apart until I get a replacement since it's my primary vehicle.
Thanks again I'll update as I go.

See less See more

Save

mrboca

· #26 · May 26, 2017

The swash plate compressors are pretty hardy. Usually the control valve goes bad. You need to keep the static pressure at about 70 to 80 psi at the low side when the compressor is not running. If you can find a control valve suitable for your compressor at a JY it may be worth a shut before a major surgery. The new ones cost about 20 to 25 bucks but you need to know which one to buy.

Save

Reactions: 1

55Benz

Discussion Starter · #27 · Aug 3, 2017

Thanks everyone for your help.
I discovered my compressor was definitely bad. Even though the clutch would still engage the shaft to the compressor must have been broken causing the compressor to not operate. I replaced the compressor with a rebuilt one, and also the dryer. Got a loaner pump from Autozone and she's blowing cold again.

Save

Reactions: 1

21 - 27 of 27 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.

Top Contributors this Month