The climate system is making and odd noise. clickclickclickclickclick.... very fast repeated clicking.

It does this when heat is selected on the temp roller, and the button (marked EC) next to the off button is pushed in. It also does it when the next button to the left is pushed in. When the next button (with 2 solid arrows) to the left is in, it doesn't make the noise.

After messing about with it, I suspect the gizmo that operates the flap that directs the air through the dash vents and the floor vents may be having a problem. The sound seems to come from inside the knee pad area, just to the right of the center console.

With the ACC off, I rolled the dial to full-on A/C let chill air come out for a while, then pushed the button marked EC. I then rolled the dial to full heat. The clicking didn't happen, warm air came out the dash vents. But when I turned the engine off, then re-started it, the clicking began immediately.

Any ideas? Maybe photos of the potential problem?

__________________
.
1st MBz: 1982 300SD
2nd MBz: 1987 300SDL
3rd MBz: 1995 S420
4th MBz: 1987 190DT
5th MBz: 1984 300SD w/1983 300DT engine
6th MBz: 1999 C230k I'm 3rd owner, got it w/57,235 miles.
and manages Mom's 2007 R320 CDI

Here is a thread from the forum that seems to describe your problem. PEACH

__________________
BENZ THERE DONE THAThttp://www.peachparts.com/shopforum/...c/progress.gif
15 VW Passat TDI
00 E420
98 E300 DT
97 E420 Donor Car - NEED PARTS? PM ME!
97 S500
97 E300D
86 Holden Jackaroo Turbo D
86 300SDL
(o\|/o)

That's an interesting thread you posted, but we don`t know if he fixed his problem.
There was no closeure to what he did or if it even works now.

Redoing the solder connections works sometimes. Too much heat can damage the components on the board.
Also if there is bad components on the board. redoing the solder won`t fix the problem totally.

James Dean rebuilds Cruise Control units, does he do PBU also?




Charlie

__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

I have a spare push button unit (PBU) that was from a 190 I no longer have. So I took it apart for practice. I can see a couple cold solder joints in this unit.

It makes sense that the rapid clicking sound is a relay that doesn't fully engage, and is controlled by the PBU.

That means the problem is either the relay, or the PBU. I'd like to find the relay and test it before I remove and tear into the PBU.

Any suggestions on the relay(s) location?

__________________
.
1st MBz: 1982 300SD
2nd MBz: 1987 300SDL
3rd MBz: 1995 S420
4th MBz: 1987 190DT
5th MBz: 1984 300SD w/1983 300DT engine
6th MBz: 1999 C230k I'm 3rd owner, got it w/57,235 miles.
and manages Mom's 2007 R320 CDI

The innards of the push-button box in my 1984 & 85 300D's is mostly relays. They are soldered to the circuit board. You can find photos on this site. I might have even posted some. The relays are large (~6 total) and exposed, so easy to see how they work. A cold solder joint (cracked) can certainly cause "relay chatter".

__________________
1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

I think I'll go to the Pick&Pull and get a spare PBU. There are 3 donors from 83-85, my 300SD chassis is a 1984.

I'm in Idaho and the heater is presently working. When I fiddle with the PBU a bit the clicking stops and the heat comes out of the windshield vents and the side-dash vents.

The last thing I want is to do is "fix" it until it is well and truly broken before Spring.

__________________
.
1st MBz: 1982 300SD
2nd MBz: 1987 300SDL
3rd MBz: 1995 S420
4th MBz: 1987 190DT
5th MBz: 1984 300SD w/1983 300DT engine
6th MBz: 1999 C230k I'm 3rd owner, got it w/57,235 miles.
and manages Mom's 2007 R320 CDI