Instrument Cluster

UK forum for general and technical discussion about the Z3 roadster
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leighrowland
Joined: Mon 16 Oct, 2017 10:20
Posts: 3

  Z3 roadster 1.9i

Instrument Cluster

Post by leighrowland »

Hi,
I have a 1999 Z3 1.9l .
When the weather is cold (not freezing) on starting the car from cold neither the Fuel Gauge, Water Temp Gauge or the Rev Counter work. After running the engine for 15 minutes and warming up the interior, on restarting the gauges work.
Anyone have an idea of the source of the problem and a fix.
Thanks in anticipation,
Leigh
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colb
Joined: Sat 05 May, 2012 22:46
Posts: 690

  Z3 roadster 1.8 TU
Location: Newport South Wales UK

Re: Instrument Cluster

Post by colb »

Sounds like dodgy or dirty connections on the back of the cluster. Best would be to remove the instrument pod two screws and pull it forwards so you can see the wiring connections on the rear, inspect the connections for any that are loose. Pull the connectors off and replace them to ensure they are tight good connections. The fact that your fault happens when in cold weather and then clears when the car is heated would lead me to thinking its dodgy connections.
Colb
1999 BMW 1.8 Z3
2003 BMW 2.5 Z4
1998 Honda Deauville NT650V
LaRy
Joined: Mon 12 Nov, 2018 17:47
Posts: 149

  Z3 roadster 2.8

Re: Instrument Cluster

Post by LaRy »

I would start just like colb wrote. I looked into the electric wiring diagram for the Z3, and the components you are describing are in someway connected in the cluster, maybe common stabilized power supply circuits.
Something happening in old cars is that some soldering is cracked on the cluster circuit board. This is happening because of temperature and vibrations. The fact that it is sometimes working and sometimes not, is a sign of poor connectors or soldering cracks.
If you take the cluster out, you can start to check every singel soldering in the electronics by a loupe, checking for cracks in soldering, especially around the heavy component soldering pins. When found, or suspected, you can re-solder. Most probably, you can also send the instrument cluster away to some expert.
But, to get the instrument cluster out, it is an advanced job. The steering wheel must be removed, and that is connected to the steering wheel sensor and airbag. You need to know what you are doing, and how to do it in a proper way. It is a certain procedure to follow to get the sensor back in correct position.
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colb
Joined: Sat 05 May, 2012 22:46
Posts: 690

  Z3 roadster 1.8 TU
Location: Newport South Wales UK

Re: Instrument Cluster

Post by colb »

No need to remove the steering wheel, just undo the two screws then lift and pull forward, there is enough room to tilt the pod and get your hands in to get at the wiring plugs to disconnect them and lift the pod out for closer inspection of the sockets and solder connections. Had mine out a couple of times its easy.
A guide is in the knowledge base here for when you need to change bulbs viewtopic.php?f=18&t=33125
Colb
1999 BMW 1.8 Z3
2003 BMW 2.5 Z4
1998 Honda Deauville NT650V
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Robert T
Site Admin
Joined: Mon 12 Jun, 2006 10:35
Posts: 10170

  Z3 roadster 1.9
Location: Cheshire

Re: Instrument Cluster

Post by Robert T »

I have the same problem with my car every now and again. It is so intermittent (like once every 6 months) that it has so far been impossible to trace. My conclusion thus far is a short or open circuit that causes the cluster to go into safe-mode and not drive the gauges. The rest of the cluster seems to work fine, including the mileometer. It seems to reset after you remove the key long enough for the immobiliser to cut in.

So how often does this happen for you?

Cheers R.

Sent from my SM-G950F using Tapatalk

Arctic Silver '99 Z3 1.9 & Black '59 Frogeye 1275cc
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LaRy
Joined: Mon 12 Nov, 2018 17:47
Posts: 149

  Z3 roadster 2.8

Re: Instrument Cluster

Post by LaRy »

Thank you colb for the information, concerning no need to remove the steering wheel, good to know. I read it in the Bentley Publishers Service Manual that the steering wheel must be removed.
leighrowland
Joined: Mon 16 Oct, 2017 10:20
Posts: 3

  Z3 roadster 1.9i

Re: Instrument Cluster

Post by leighrowland »

Thank you all very much for your advice.
I will remove the instrument cluster and check the connections.
Will report back in due course.
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