C900 Instrument Cluster
The second stage of this project is removing the instrument cluster.
Before pulling the cluster out, we need to disconnect it.
Depending on the model year and included features of your car, you should have the following things to disconnect prior to pulling the cluster out.
NOTE: This procedure is based on a 1989 900 Turbo. Your car's instrument cluster may have different connectors for the speedometer cable and cruise control speed sensor.
- Speedometer Cable
- Cruise Control Wiring Harness
- Instrument Cluster Harnesses (2)
- Dash Dimmer Harness
Because my camera is too large to get in behind the cluster, it is necessary to describe each of the above.
Remove the left speaker cover and disconnect the speaker (being careful not to lose the speaker wire.)
If you look into the dash through the windshield from outside, you'll get a good idea of where everything is.
Of course, if you're head is small enough to fit in there and see up close, then be my guest.
The Speedometer cable is an easy one. It is the black tube that goes into the back of the speedometer.
The cable is held in place by a clip or latch that can be easily popped off. Pull the cable out of the speedometer where it will not be in the way.
The Cruise Control harness is also easy. If you're car has cruise, it will be a 3-pin connector which also attaches to the back of the speedometer.
It is located to the left of the speedometer cable (if viewing the cluster from the back) and slides off with relative ease.
With all wiring back here, use extra caution so as not to break or damage the wires.
This is the back of a 1989 speedometer. You can see the 3-pin connector for the cruise control speed sensor wiring.
Also, on this year's speedometer, the speedometer cable has a clip that snaps over the stalk on the back of the gauge.
This is the back of a 1983 speedometer. I believe that the angled circuit with the 2-pins is the older style speed sensor connection, but I cannot be sure.
On this year's speedometer, the speedometer cable snaps over the stalk on the back of the gauge and it held in place by the metal clip on the gauge stalk.
The second, threaded, fitting to the left of the speedometer cable stalk is the EXH box attach point.
Disconnecting that box from the speedometer will prevent the EXH light (older models) from coming on again.
Instrument Cluster Harnesses...these bad boys can really be a pain. You must exercise extreme caution when removing these from the cluster.
There are a lot of wires in these two harnesses and they are very cheap in construction.
The harnesses are rectangular and go into the extreme left and extreme right sides in the back of the cluster housing.
I recommend working them out of their sockets in a rocking motion, not pulling on the wires themselves. Pull the wires as a last resort!
When they come free, they sometimes bring the socket housing with them. The harness itself is white plastic, and the socket housing is black.
So if you pull out a group of wires with a black harness, then you pulled too much. Not to worry, you haven't damaged anything.
||Primary wiring harness socket with socket housing still attached (black connector)
||Primary wiring harness socket with socket housing pulled free.
||The cluster is held into the dash with four torx screws. There are two on the left and two on the right. Remove them and the cluster should be easy to free from the dash.
Remove the instrument cluster from the dash. If either socket housing came off with a wiring harness, remove it from the harness.
Now is also a good time to clean out the dust and dirt that has accumulated behind the dash over the years. It is also a good chance to inspect and replace the vacuum lines for cruise control, turbo gauge, and heating vent controls.