Are we good, or what!

Just did the testing to confirm that the mechanic is actually quite a good guy, and that I don't have any further work to do on the A/C at this point in time:

* Looked under the hood at the KLIMA socket. Lo and behold -- there is a real, honest-to-god KLIMA relay occupying those pin-holes now! Removed it to see what is going on.
* Pin #10 is now receiving a ground signal to activate the A/C (he must have swapped out the CCU...?)
* KLIMA is now working & engaging the A/C compressor.

The day was 67~72 degrees F.
At idle, Eleanor was reading 47-78F at Max A/C at the vents. Decided to take her for a spin.
At highway speeds, vent temps got down to 36~37F. Quickly bounced back up to 46~48F upon exiting the freeway and slowing down to in-city speeds.

As far as I know -- that's total spec.

Sweet!!

What do you guys think?

I think I owe my mechanic a nice card. And maybe something else, if he wound up giving me a KLIMA unit (what is that, roughly $200 value?) for free... at least a six-pack of beer, right? Some chocolate? He didn't charge me a thing, as this work fell under the 12-month warranty for work I paid for last year.

cheers,
~Garlynn

Good going, just in time for a little heat wave headed our way, its supposed to be in the 90's inland the latter part of this week
Maybe SF will get up to 80. Thats a heat wave out here.
find out where he eats out and buy a gift certificate.
Maybe I need to take my AC over there. PM me with details etc.

Reid

__________________
'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!

If you need HVAC work done in SF I've had good luck with aLouis Raditor on Divisadero (no affiliation etc.) They've worked on my 124 more than once and seem to understand the system.

One interesting note for those who aren't getting full cooling. I recently replaced my fan motor and discovered that one half of my evap. core was completely packed with dirt so no air was getting through it. I carefully vacuumed it all away and it made a pretty big difference. The other problem (which I have yet to fix) is replacing all my pods under the dash.

__________________
LRG
1987 300D Turbo 175K
2006 Toyota Prius, efficent but no soul
1985 300 TDT(130K miles of trouble free motoring)now sold

I sent my '87 300D to get the A/C recharged, new condensor and dryer/accumulator and a new dryer hose and a new expansion valve . . I hope the flaps all work or I'm going to need to remove the dash for those pesky Pods, a cursed job!

__________________
'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!

Heya,

Well, the A/C works now. Oh, does it work! Just drove up from San Francisco to Portland on Hwy 101, and used it the first day coming out of the Bay Area. PLENTY cold.

However, on the second day, going through the redwoods, we had it set on the economy mode... you know, the button just left of 0 (off). Well, the engine was making some funny noises going up the hills, and the vents were blowing really cold.

Then, the vents stopped blowing at all. That's when I decided to pull over.

Sure enough, the return (low pressure) line was completely covered in ice & snow. The compressor was turning on even in ECONOMY mode!

I unplugged one of the wires on the pressure switch to dis-engage the compressor, poured lukewarm water on the line to melt the ice, and we drove off with the vents working again (and more power going up the hills).

Any idea why the compressor wasn't shutting off in economy mode? And why the icing up of the low pressure line would cause the cabin vents to stop blowing any cool air at all, even in economy mode?

Eleanor's got a brand-new KLIMA module... but, the pressure switch is old. The shop owner apparently installed the KLIMA for free.

Any help would be much appreciated! I have a feeling we'll want the A/C to be trouble-free for the return trip back down I-5 in a week.

cheers,
~Garlynn

It's a bit of a reach but can you check the part number of the Klima? I don't know if Diesels and gassers have different PBUs but I know they have different Klima relays.

The original Klima is something like 001-545-80-05. The revised Klima that does away with the start-up delay is 003-545-69-05. If it's 002 545 13 05 or anything that begins with 002, it's a gasser Klima.

With the PBU on Econ and compressor running, disconnect the low pressure switch. If the compressor disengages, the problem is upstream and likely the PBU. If the compressor stays engaged, it's either a faulty Klima or someone jumped power to the compressor between the Klima and the compressor. Or if we've established that the PBU sends a ground signal to the Klima, it's very possible you have a grounded wire between the PBU and the Klima. Checking behavior with the low pressure switch disconnected will help you isolate.

Sixto
87 300D

I once saw some odd behaviour on the '87 when the battery was failing. The regulator cranked up the voltage so high in an attempt to charge the dead/dying battery that the a/c switched on while in economy mode. It may be worth checking out the charging system, though if your car doesn't need to be jumpstarted on a regular basis it's an unlikely problem.

It's also possible the EC button is flaky or simply wasn't pressed in all the way. Did you try the Off button?

Lack of airflow was caused by ice forming on the evaporator fins, blocking the flow of air through the evaporator. It's a secondary symptom of the compressor running and not being cycled off periodically by the PBU. Fix the root cause and it won't happen again.

- JimY

Just pulled the KLIMA and am looking at it now. On one side, it says:

3.701.100
A/C Compressor * D-Clima * Kickdown
49.07

On the top, it says:

K*A*E
KAEHLER Automotive Equipment
Relais/Relay 12 V
Made in Germany PA 6 -- GF 30

Am I correct in thinking that this means it's an aftermarket KLIMA? Any way to tell if it is the *correct* aftermarket KLIMA?


Yup, did that. With PBU on Econ and compressor running, I disconnected the low pressure switch and the compressor disengaged.

Is there any possibility that this is due to a faulty low pressure switch?

cheers,
~Garlynn

Jim-

The CCU is brand new, buttons work A-OK, as far as I can tell. The off button definitely turns off the compressor. It's just that the ECON button does not.

Glad to know that the ice was the only thing blocking the airflow. Is it likely that the ice did any permanent damage to the system, or is the ice just a harmless symptom of a problem that causes icing?

thanks,
~Garlynn

The ice formation should not cause any lasting problems.

I think Sixto's test shows that the problem must be with the PBU. As I recall, the "turn on" ground signal from the PBU passes through the pressure switch before hitting the Klima. That the compressor stopped when you disconnected the pigtails shows that the PBU was ordering the compressor to turn on, the Klima was just following orders. I'm thinking defective PBU at this point.

- JimY

This is a common failure mode on the '87 300D, I've experienced it on two: The A/C compressor will decide to run with the PBU set in economy, it will even start to blow air and run the compressor with the PBU set to off some times. Cycling through the normal and then economy modes will temporarily shut down the compressor usually.

__________________

Gone to the dark side

- Jeff

OK, so we drove back down from Portland to Oakland yesterday, and hit some decent heat beginning in southern Oregon and continuing into the Bay Area, requiring the use of the AC, so I plugged the pressure sensor back in outside of Grants Pass. By the time we hit Ashland (less than an hour later), the system had iced up and stopped blowing cold. We stopped in Ashland for about 45 minutes, giving it time to de-ice. It blew cold up into the mountains around the California-Oregon border, but then it iced up again. Luckily, the temperatures did not get above the 80s, as the AC would blow cold, then blow ambient and with slower velocity as the system iced up.

I suppose I need to call the shop that just did all this work, and report what is going on -- but first, does anybody have any similar experiences with an AC system that continually ices up? What did you do to solve it?

thanks,
~Garlynn

Icing usually indicates one or more of the following:

Low refrigerant pressure
Low evaporator airflow (blower or clogged evaporator from leaves etc., is it a 126?)

Coupled with a bad evap. temp sensor (aka: freeze stat)

__________________

Gone to the dark side

- Jeff

Whats the start-up delay you mention, Sixto?
I have a odd thing happening with my wife's '87 300Dt. The AC works fine, on a hot day we drive a half hour to our destination and when we arrive we leave the car, once for about an hour and for two hours on another day. When starting the trip back there's no AC at all. Drove several miles and it blows hot all the way. The pressure and suction lines aren't cold and the clutch isn't pulling in on the compressor. This has happened twice just the same each time except the second time it happened I stopped about half way home (15 miles) for about 5 minutes while she was shopping and let the car sit, engine off. When starting up from there AC blew cold again! Bonkers
I'm thinking it could be an overpressure or something activating the switch on the dryer. Could this be from too much freon (R12)?
I can swap the Klima from the other car I suppose as a quick diagnostic but just wondered what the start up delay is?
Oh yes, its a new CCU not sure the age of the Klima though.
Thanks, Reid

__________________
'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!