Most E30s have cluster problems, either one or multiple gauges not working or service indicator lights flashing etc...
I just wanted to list some common problems with them for those who might want to repair them. I can't live or drive even 10 miles if something isn't working properly in my cluster, so I've probably worked so far with about 20 clusters (early and late model).
Some common problems are:
- missing rear nut on the back of the fuel and / or temp gauge.
- leaking si board batteries
- not leaking batteries but dead si board
- burnt traces on the si board
- burnt traces on the main cluster board
- colder solder joints on the main cluster board
- broken odometer gears
These are some of the most common problems.
Obviously other things will affect your cluster not working, such as blown fuses, bad wiring or connection from the diff. sensor, from the fuel level sensors(s) and/or from the temp sensor.
Always start with checking that you don't have blown fuses, don't just inspect them, check them with a test light or DVM. Check that the connection at the diff. sensor isn't broken or loose. Check the connection under the hood to the temp sensor.
To test the fuel level gauge, you may also remove the fuel level sensor(s) and verify that their resistance changes while the float inside the sensor is moving. The "empty fuel" warning light is also triggered by the fuel level sensor. The fuel level gauge in the cluster aren't the same for ALL clusters, they have changed over the years to reflect the change in fuel tank volumes and the fact that some fuel tanks have TWO sensors.
Some cars have one fuel level sensor, and some have two. Keep in mind that if you have TWO, they work in SERIES, meaning if one of them is BAD it will affect the reading from the 2nd unit as well.
If all of the above are ok, remove the cluster and inspect it first, some problems are easy to spot (broken gears, missing mounting nut(s) on the fuel/temp gauges, burnt smell/burnt traces).
Cold solder joints aren't as easy to spot, but they result in your cluster having intermmitent problems. They basically cause "bad connections" that sometimes work and sometimes don't as you are driving your car.
From my experience, VDO and MotoMeter boards can be interchanged.
Hope this helps.
Now on to pictures.
Very common for the small gear to strip, when you replace it, buy a new gear, don't even bother putting a used one in it's place as it's not even worth the hassle. Most are so old that they'll break while you try to remove/install them.
The speedo motor has very fragile leads, they are easy to break but I've been able to solder them back on with a good soldering station and steady hand.
Usually this odometer motor doesn't fail, but it can be removed and replaced w/o too many problems.
The two leads on the bottom are soldered to the speedo/odometer unit and feed the speedo motor. the other 3 feed the odometer motor.
You'll need to remember where everything goes to put it back together :)
Now, the main cluster board is where you'll usually find bad/cold solder joints, in the areas where the plugs at the back connect to the cluster.
rear side of the main board, not too complicated. inspect to make sure nothing is burnt.
I usually re-flow these joints with a small soldering tip, this is where I've seen them develop bad connections.
The small board with 2 bulbs and leds for the SI board sometimes also develop bad solder joints causing only SOME leds to come on, or have a burnt bulb.
I just wanted to list some common problems with them for those who might want to repair them. I can't live or drive even 10 miles if something isn't working properly in my cluster, so I've probably worked so far with about 20 clusters (early and late model).
Some common problems are:
- missing rear nut on the back of the fuel and / or temp gauge.
- leaking si board batteries
- not leaking batteries but dead si board
- burnt traces on the si board
- burnt traces on the main cluster board
- colder solder joints on the main cluster board
- broken odometer gears
These are some of the most common problems.
Obviously other things will affect your cluster not working, such as blown fuses, bad wiring or connection from the diff. sensor, from the fuel level sensors(s) and/or from the temp sensor.
Always start with checking that you don't have blown fuses, don't just inspect them, check them with a test light or DVM. Check that the connection at the diff. sensor isn't broken or loose. Check the connection under the hood to the temp sensor.
To test the fuel level gauge, you may also remove the fuel level sensor(s) and verify that their resistance changes while the float inside the sensor is moving. The "empty fuel" warning light is also triggered by the fuel level sensor. The fuel level gauge in the cluster aren't the same for ALL clusters, they have changed over the years to reflect the change in fuel tank volumes and the fact that some fuel tanks have TWO sensors.
Some cars have one fuel level sensor, and some have two. Keep in mind that if you have TWO, they work in SERIES, meaning if one of them is BAD it will affect the reading from the 2nd unit as well.
If all of the above are ok, remove the cluster and inspect it first, some problems are easy to spot (broken gears, missing mounting nut(s) on the fuel/temp gauges, burnt smell/burnt traces).
Cold solder joints aren't as easy to spot, but they result in your cluster having intermmitent problems. They basically cause "bad connections" that sometimes work and sometimes don't as you are driving your car.
From my experience, VDO and MotoMeter boards can be interchanged.
Hope this helps.
Now on to pictures.
Very common for the small gear to strip, when you replace it, buy a new gear, don't even bother putting a used one in it's place as it's not even worth the hassle. Most are so old that they'll break while you try to remove/install them.
The speedo motor has very fragile leads, they are easy to break but I've been able to solder them back on with a good soldering station and steady hand.
Usually this odometer motor doesn't fail, but it can be removed and replaced w/o too many problems.
The two leads on the bottom are soldered to the speedo/odometer unit and feed the speedo motor. the other 3 feed the odometer motor.
You'll need to remember where everything goes to put it back together :)
Now, the main cluster board is where you'll usually find bad/cold solder joints, in the areas where the plugs at the back connect to the cluster.
rear side of the main board, not too complicated. inspect to make sure nothing is burnt.
I usually re-flow these joints with a small soldering tip, this is where I've seen them develop bad connections.
The small board with 2 bulbs and leds for the SI board sometimes also develop bad solder joints causing only SOME leds to come on, or have a burnt bulb.
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