Cluster Panel Problem - PeachParts Mercedes-Benz Forum

nyko46 · #1 03-29-2015, 05:03 PM

My 1984 MB 300SD dash board was not illuminated due the bad rheostat (pot).
After removing the entire dash board and crossing the pot and installing the dash board again, it did not work correctly. Lights were replaced but not all of them are working correctly and some of them no longer working. It is worse than before. For example: light for glow plug is not working, brake light is on all the time, high bean light indicator is not working, seat belt light and battery light are not working, fuel gauge is showing empty after the car starts. Other instruments like RPM and speedometer is working correctly.
The car is running but cluster is not. All fuses are good including the cluster fuse.
I tested few times but I was not able to get it working.
Please give me some help to get it working again.

TnBob · #2 03-29-2015, 06:54 PM

Sounds like your bulb connections on the board have gotten stray wires or something metalic across them or in the bulb socket itself.

nyko46 · #3 03-29-2015, 07:38 PM

If it happened do you think that the board got damaged or only stop working?
Minutes ago I drove the car and it the problem still the same.
Also after this problem the CCU stop working and as I said before, fuel gauge and oil pressure are not working. Fuel gauge is showing empty and it is full and oil pressure gauge is showing maximum pressure even with the engine not running.
It all happened after repairing (crossing the rheostat).

JamesDean · #4 03-30-2015, 04:12 PM

It sounds like the big connector is off by a pin.

There is a big connector that has some 15 wires in it that go to most of those bulbs.

Usually the connector has a D shaped locating pin so that one cannot misalign the pins. However these can break off and then you have to align it manually.

When you removed/installed the cluster did the big connector have its locating pin on it? Or was it broken off?

nyko46 · #5 03-30-2015, 08:42 PM

Yes it was broken but I aligned it matching the pins with the female plug.
The crazy thing happened when I turn on the ignition key after the cluster installation. The radio panel started to blink, and turned off right after blink for few times.
Today I drove the car to go to work and I noticed couple different behavior from this problems.
Here they are:
Driving at night the battery light stay on, the fuel gauge stay on low fuel, the high bean light indicator stay on at all times (low or high bean), the temperature gauge stay as cold.
Driving at day time the brake light stay on, the fuel gauge stay off, the temperature gauge works, the high bean light indicator stay on at all times.
Another issue is: during night or day time high and low bean lights of the car stay on constantly and only turns off when I turn the car engine off.
The lights are turned on as soon the engine starts and stay on until I turned the engine off.
Day or nigh the light for glow plugs does not work.
Today my radio and my central door lock system stopped working.
Can all this problem be started with my cluster or it is a

coincidence?

JamesDean · #6 03-30-2015, 09:43 PM

I thought it might have been broken. Can you give me the details of how you aligned it?

nyko46 · #7 03-30-2015, 10:23 PM

When I removed the round plug the D pin came broken from the cluster.
I then glued it to the connector in the same location according the the mark left on connector.
I then plugged it on the cluster. As it didn't not worked, latter I removed it from the cluster again and the D pin wasn't there again. Then my only chance was to plug it aligning the pins using as guide two pins that are spaced differently than others.
These two holes in the connector match with the two pins on the cluster. With power off I tried and the connector will go into the pins only if these two pins and holes are aligned. There are no other way to plug connector and cluster pins if these two holes and pins are not matching one with other. This is the way that I installed the cluster in place after the first time when I had trouble.
I really don't know why other parts of the car like radio, fuel and temperature gauge are not working after the first time.
I need help and I am willing to give all necessary details of the problem as I gave today.
Thanks

JamesDean · #8 04-01-2015, 11:38 PM

Hi nyko,

Did you have any more luck with this?

nyko46 · #9 04-02-2015, 05:11 PM

James, I did not had any other improvement better than it was before. I mentioned CCU for "climate control unit"
I still wondering why all other instruments like fuel gauge, engine temperature gauge, oil pressure, and the glow plug light are all crazy right now. Even the emergency lights are not working. If it was the case, could a wrong connection of the round connector cause all these damages? I didn't noticed any burning wires, short circuit or any smelling of anything burning when I connected for the first time.
Cluster light for high bean is on at all time, battery light and brake light are also on. There are not on single light illuminating the cluster, the CCU and the windows switches. I just got my CCU unit and the central door locks and my radio working again. I reset the radio and it is worked again but it went bad when I connected the cluster for the first time and turned the ignition key to on position
As I remember all connectors behind the cluster can be connected only in one position. As the big D was broken, the round connector is the only one that have a change of be connected wrong but it was inspected and re-connected again. Do you think that the first connection can cause damage to other parts of the car?
Can the cluster itself be damaged and no longer working correct?
I am really disappointed with this problem not understanding why all this happened and after few tries it still not resolved.
Any help is really appreciated.

Thanks

JamesDean · #10 04-03-2015, 12:18 PM

Yes mis-aligning that connector can cause lots of problems.

What I would do if I were you is:
1) Pull instrument cluster
2) Remove the fuel/oil/coolant pod.
3) There should be pin numbers silk screened on the otherside of the circuit board.
4) Use these to mark pins on the back of the circuit board where the connector goes.
5) Re-install pods.
6) Re-align pins based on the numbers you wrote on back.

You can vaguely see the numbers in this photo, they are a bit out of focus.
http://i.imgur.com/1QbabaW.jpg

If you orient that connector wrong it MAY damage something. I am not sure. I dont remember the pin out of it so if by mis-aligning the connector you've applied a voltage to something that should not have received that voltage..then maybe something got damaged.

I do service work on the instrument clusters so if you would like, you can pull the cluster and send it to me. I can check out it for you, etc.

DieselGuy53 · #11 04-03-2015, 02:16 PM

NYKo46,

JamesDean is correct. It is very likely the big connector is misaligned. BTDT my D pin broke. Took me 12 tries to finally align mine. I then used a marker and mark alignment line. Went to a junk yard, got one D pin then glued it in.

Keep trying and you will get it to align correctly.

nyko46 · #12 04-03-2015, 10:57 PM

Tomorrow, my day off, I will remove the cluster and follow James instructions.
The only problem is that the electric cable wired to the big connector is too short giving a little room to install it to the cluster.
Anyway, I want to see my car cluster working better than it was before.
Thanks for all very good information and the help for everyone.

nyko46 · #13 04-04-2015, 10:13 PM

Yes folks, I got my cluster panel working again.
As suggested by JamesDean and DieselGuy53 I removed the cluster panel, brought it inside of the house and inspected all parts of the circuit board.
With a multimeter I checked all diodes, resistors and all soldering connections.
Also check all lights sockets, and continuity of all traces and found all of then OK. I gave special attention to the round connector male and female for numbering to make it match later when installing in the car.
The round female connector, other than the D mark, have only number 12 and 13 stamped in it.
The round male connector have numbers from 1 to 15 marked in it on the back of the board.
I then wrote these two numbers to the pins in front of the board to use them as a guide when connecting to the female connector. Since the D mark is broken this was the only way to get those two connectors installed properly.
In the car I paid special attention to connect 12 male to 12 female and the same for number 13.
Expecting the best, I turned the car and the lights on and the cluster panel worked like new.
All gauges and lights for each specific function are now working.
That result made my Saturday complete after many tries and couple frustrations from previous tries without results.
Thanks to everyone suggestions and help I have now my cluster working again.
Special thanks for all people that helped me with their technical knowledge and suggestions.
Thanks.

TnBob · #14 04-05-2015, 02:33 PM

We all learn from threads like this.
Id suggest a written note stuffed into the connector wiring for next time or next owner.