Written By: Nicolas Siemsen · Removing Mercedes W123 Instrument Cluster If your odometer stops...

Removing Mercedes W123 Instrument ClusterIf your odometer stops working, your speedometer cable needs to be replaced, or other issues

arise with your instrument cluster you will need to remove it before continuing with the work.

Written By: Nicolas Siemsen

Removing Mercedes W123 Instrument Cluster Draft: 2014-05-12Guide ID: 25231 -

This document was generated on 2019-09-18 03:32:22 PM (MST).

© iFixit — CC BY-NC-SA www.iFixit.com of 10

INTRODUCTION

There are a lot of important components in your instrument cluster, and it's only a matter of timebefore you'll need to pull it out to fix something. It's not such a daunting task, once you know a fewtricks. This guide should help with this task.

TOOLS:10mm Wrench (1)




http://www.amazon.com/TEKTON-21271-10mm-Combination-Wrench/dp/B000NPUL0G/ref=sr_1_1?ie=UTF8&qid=1388418341&sr=8-1&keywords=10mm+wrench

Step 1 — Instrument Cluster

Begin by disconnecting your battery,pulling off the negative (-) groundcable.

This is required for this process!There is a constant 12v supply ofpower to your car's clock, evenwhen the key is off. If you attempt topull the cluster out with the batteryconnected you will burn up part ofyour cluster's circuit board, or worseyet hurt yourself.

Step 2

Then remove the driver's side kickpanel. See the kick panel removalguide for help with this task.




https://www.ifixit.com/Guide/Disassembling+Mercedes+W123+Kick+Panel/22838

Step 3

The cluster is held in by tensionalone. There are no fasteners.

Reach up under the dash, feel yourway past any wires and/or soundinsulating material until you cantouch the back of the cluster. Thenpush it firmly outwards towards thesteering wheel.

Step 4

Once the cluster starts to come out,you can pull it further out by theupper edge.




Step 5

Pull the cluster out until you feel thetension of the speedometer cable.

Normally, there will be just barelyenough room for you to get yourhand behind the cluster. You willneed to feel around the center of thecluster, behind and to the right of thecenter of the speedometer cable, forthe connection for the speedometercable.

The cable screws on to the back ofthe cluster with a knurled knob. It isto be loosened by hand. No toolswill be necessary to unscrew this.Unscrew the cable until it is free ofthe cluster.

If your speedometer cable isespecially taut behind the cluster,you may need to go back to step 2and try to remove it by feel beforepushing the cluster out by hand.




Step 6

With the speedometer cabledisconnected you will be able to pullthe cluster out further for moreworking room.

Starting on the right side, begindisconnecting the items that attachto it.

First, you will pull out any light bulbsthat plug in to the right hand side ofthe cluster. On a diesel W123 thiswill include the glow plug bulb andseatbelt bulb. Then unplug thespade connector for the powersupply to the clock.

Step 7

Next, unplug the two small plugs near the middle of the cluster.




Step 8

Next, use a 10mm wrench tounscrew the oil line from the oilgauge.

Lastly, unplug the large round plugon the far left of the cluster, downand to the left of the oil gauge fitting.

Step 9

With everything disconnected youcan now remove the cluster,carefully working it up and out pastthe steering wheel.




Step 10

With the cluster removed on this car,let's take a second to identify someof the connections:

Speedometer cable

Oil line fitting

Small plugs for clusteraccessories and lighting

Large primary plug

Not pictured are the wires and bulbsfor the glow plug and seat belt light,and the spade plug for the clock.Keep track of which bulb went inwhich socket - the wires will bedifferent colors. On this car the wirefor the seat belt light was green andthe glow plug bulb wire was blue.




Step 11

You can now take the cluster to your work bench to undertake whatever job you removed it for.

Let's review the components, both front and back:

Oil pressure gauge, gas gauge, and engine temperature gauge

Speedometer, odometer and trip odometer

Tachometer and clock




To reassemble your device, follow these instructions in reverse order.

Step 12

And a bit more detail about thecomponents on the back of thecluster:

Light bulb sockets (some areused, others are blanked out)

Speedometer cable connection

Rheostat (dimmer) control

Oil line connection

Clock spade connector (note+12v symbol, this is the constant12v supply that can damage yourcluster if battery is notdisconnected)

Large primary cluster pins

Accessory plugs




Written By: Nicolas Siemsen · Removing Mercedes W123 Instrument Cluster If your odometer stops...

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