Is it permanatly grouund, or is it a switched ground? Say through a low side transistor/FET driver?

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

It's a switched ground from the CCU. I'll leave the specifics to someone more versed in electronics.

If it's electronically switched, then looking at resistance isn't going to work. You need to look at voltage. When not on, it should be at battery voltage. When the CCU turns it on, it will switch the driver on and you will see very low voltage, something like .25 to .75 volts, depending on the driver type and the current draw.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

I'm sure it's switched with a relay in the CCU. When not "on" its open. When the CCU turns it "on" it provides a ground to the Klima. You won't see any voltage.

This may be of assistance - http://mb.braingears.com/126_DISC1/program/Climate/1986.pdf

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

It could very well be.

Old fashioned relays!

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

well well well
I finally got most every thing put back in its place after replacing all the vaccume pods,cleaning and flushing the evap core and everything else in the car....
the console was dyed along with the dash while it out; the carpets and most every other panel that needed it in the car also got a good going over and dying.

and guess what .....after putting every thing back together the climate control appears to work.....for the time being....the ac turns on, the heat/ defrost turns on ....wowow ....amazing....and i did nothing but put it back together.

heres my problems now:
when i was in the process i took the cluster out and cleaned it well..... now the clock works when it didnt before and the fuel gauge seems to work with out fluttering wildly like it did before...BUT

the odometer wont roll
the temp gauge doesnt register anything
and the oil pressure is pegged at 3
i have made sure all the connections are correct and tight and all the fuses seem to be fine.

also the seat switches only work with the door open

Where do i begin???

Has to be a disconnect between the cluster and the wiring harness. None of the devices in the cluster are receiving any inputs.


Welcome to the world of M/B. They also work with the keyswitch in the II position.

I have tripple checked all the conections and still have the same results
checked all the little pegs to make sure they were clean and pushed in all the way even wriggled them a bit to see if there was a loose or broken wire

odometer doesnt work
speedometer does

tack works
clock works and keeps good time(when it didnt before)

fuel gauge works properly i believe
oil pressure pegs wide open as soon as you hit the key
temp never moves

Is the a fuse or group of fuses that control any of these non working functions?

as the car sat idling i was messing around with a test light in the fuse box and noticed that several didnt light up (possibly some of the functions didnt require power at the moment?)

any suggestions?

Actually, if you read your previous post again, your results are quite different.

Therefore, the diagnosis will be quite different.

With a properly working fuel gauge and tach, the problem is not simply a failure to plug the unit in properly.

It appears the both the oil pressure and temperature gauges have no input. If you are positive of the connections, then either the sending units are NG or the gauges are NG. If all you have done, however, is to remove and reinstall the cluster, the chances of two failures at the same moment is remote. So, it sounds like there is some information missing from the picture.

With regard to the odometer, the handling of the cluster probably led to it's demise. It's a common problem for the odometer gears to slip on their shafts. There is quite a bit of info on the forum on how to repair this issue.

You're missing a ground. The path for the seat switches is now going through a different route; the one being created when you open your door.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

The power seat relay coil is powered in run or start via fuse 17.

It's also powered via fuse two, at all times, through either the left or right front door switch. If either door is open, the relay coil gets power with the keyswitch in the off position.

The system functions as designed and there is no missing ground.

I am missing something thats for sure.

after fiddling with everything i dare fiddle with the cluster performs the same
still non working is the odometer & trip odometer, temp gauge, and oil pressure.Everything else works fine it appears.

I took EXTREME care when i had the cluster out not to do any damage to it.

The seats cant possibly be working as designed....
the seats work when the car is off but only with the door open.
the seats work when the car is on but only with the door open.

the passenger side seat switch is removed from the car.... would this cause the problem above?
You may be asking yourself ....if its removed from the car how the heck will it work??
The drivers side switch is attached to the door
The passenger side switch is not.... i take a test light,hook the clip to a ground and put the probe in the wire plug i want to, to get the seat to do what i want it to.

Back to the gauges....
IS THERE A TEST i can perform to see what the problem is with the
oil pressure?
temp gauge?
odometer?

Your help would be greatly appreciated

Oh one other thing ...when i hit the reset button for the trip odometer i can see that at least those little round numbers must be attached to the shaft, because they chatter a bit when the reset button is pushed.

OK, correct, they don't work as designed. I wasn't aware of the fact that the seats don't work with the key in the No. II position.

First thing is to remove and replace fuse #17 and clean the contacts. See if this brings the seats back with the ignition on.


Remove the cluster.

Look for any black wires with pink stripe.

You'll find one going to the tach on socket #7, and a jumper from there to socket #3 on a different plug and a jumper to socket #12 on a third plug over by the far side of the cluster.

With the key in run, all of these wires must have voltage. My bet is that one of them does not.

I thought he said that it worked ONLY when the door is open....

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)