r107 instrument cluster - gauges not working properly

[Viajero]

I disassembled the instrument cluster of my 107 today to clean it. Upon putting it back together and reinstalling it, the following problems are happening:

1. the gauges in the left hand dial - the fuel gauge and the temperature gauge, are not working properly. they indicate the fuel/temperature as higher than actual. Additionally, the fuel gauge is 'trembling'.

2. When I turn on the headlights, both indicator lights in the cluster turn themselves on simultaneously (they don't flash, they just stay on). Also, turning on the headlights makes the fuel and temperature gauges suddenly jump even higher than they are.

3. The orange radiator light in the cluster is permanently on.

Before I take the whole thing apart again, would anyone have an idea of what the cause of the funny behaviour may be?

 

[mct_cars]

I'm no auto electrician, but it sounds like an earth fault of some description.

 

[Viajero]

Hi Carl, unfortunately I know next to nothing about electrics! (or any other mechanical issues for that matter - this car is my first 'project'). How is an earth fault typically caused?

 

[mct_cars]

As mentioned, not an expert myself just some of the lights and guages you mention work by completing a circuit - the sensor normally does this wherever it may be, but when you have an earth fault, that does the job instead shorting the circuit.

If all you did was remove them and put them back, I would try tracing back through what you did.

 

[Scott_F]

..... unfortunately I know next to nothing about electrics! (or any other mechanical issues for that matter.....

I don't want to seem rude but if the above really is the case then you probably shouldn't pull your instrument cluster to pieces in order to clean it !

 

[Viajero]

Hi Scott_F, I went thru two online step by step tutorials before attempting to remove and clean the cluster, and it has all come apart and back together following the tutorials -it's a two steps forward one step back process as I learn about the various bits, but am making good overall progress, and having good fun thus far!

Looks like I'll have to back track my steps again to identify the error...

 

[Scott_F]

Hi Scott_F, I went thru two online step by step tutorials before attempting to remove and clean the cluster, and it has all come apart and back together following the tutorials -it's a two steps forward one step back process as I learn about the various bits, but am making good overall progress, and having good fun thus far!

Looks like I'll have to back track my steps again to identify the error...

If it all goes OK first time every time then it's never as much fun !

 

[Druk]

It does sound like an earth fault. You're looking to trace any brown wire in the cluster or connecting socket and where it goes to on the body. Brown is earth in all Mercs.

 

[Viajero]

If it all goes OK first time every time then it's never as much fun !

Yep, and the sight of a fresh, clean instrument panel instead of a filthy, dusty one is enough to keep me motivated for a second go!

 

[Viajero]

It does sound like an earth fault. You're looking to trace any brown wire in the cluster or connecting socket and where it goes to on the body. Brown is earth in all Mercs.

Druk, that is very specific and helpful advice - I will look first for any brown wires when I next open it (probably next weekend). Many thanks.