Digital Speedometer Cluster

[buicktom61]

Hi,

my name is Thomas and I live in Germany. I have bought a 86 GN with digital speedometer cluster. The car is still in transit to me.
Does anybody know, if it is possible to change the digital speedo from mph to kilometer per hour by reprogramming it?

Thanks for your help.

Thomas

 

[Phoneguy]

The trip/reset knob will change the MPH to KMPH with a slight twist. GM actually thought about this...

Bryan

 

[buicktom61]

Thanks Bryan. Great information.

Thomas

 

[Heskahoka]

Grüß Dich Thomas, welcome the the board.

The reset button/knob will get you to the metric settings (km and Liters). BE CAREFUL, the knob is very fragile and cannot take a lot of abuse.

See the following from Caspers for everything about the digital dash:

http://www.installationinstructions.com/FYI/digitaldash.pdf

 

[buicktom61]

Thanks. This will help a lot.
Thomas

 

[buicktom61]

Hi,

does anybody know, if you can still change between miles and km/h with the Caspers 199 miles upgrade processor?

Thanks
Thomas

 

[Phoneguy]

Yes it still works
Bryan

 

[buicktom61]

My GN is now at home. I tried to twist the reset knob, but changing from mph to km/h didn't work. I only reseted the trip.

What did I wrong.
Thomas

 

[BuickMike231]

Normally you push the knob to reset the trip. Twisting it clockwise (I think) is what changes it back and forth from mph to kph. Actually rotate the knob, don't push it.

 

[DOUGGN]

Normally you push the knob to reset the trip. Twisting it clockwise (I think) is what changes it back and forth from mph to kph. Actually rotate the knob, don't push it.

that is correct

 

[MeanBuicks]

Thomas, if your GN didn't come with the Owner's Manual in the glovebox, consider picking one up. In addition to addressing the gauge cluster, it may answer other questions for you as well. Here is one mail order source: https://www.rockauto.com/catalog/x,carcode,1379820,parttype,909

 

[buicktom61]

Thanks. My reset knob turns free in the normal position. There is a soft resistance if I push the button and twist it.
Thanks for the hint with the owners manual. I ordered one right now.

Thomas

 

[GNVenom]

Your reset switch is broken. This is a common failure. It should turn about 1/8 of a turn, either clockwise or counter-clockwise to toggle from MPH to KPH. The switches are obsolete, so you would need to find a good used switch to replace it with.

Note that the odometer is likely calibrated for MPH instead of KPH - if the dash has the word "Kilometers" printed under the odometer window, it's calibrated for KPH.

The difference you'll see is the odometer will register about 20% less kilometers than the car travels. There is a special gear set for the KPH odometers, very hard to find though.

Look at:
http://www.installationinstructions.com/FYI/odometer FYI.pdf

 

[buicktom61]

Hello John,

Thanks for the information. I have no problems if it shows the actual speed in km/h and the odometer shows miles.
Is it possible to switch it to km/h with the broken switch? It only should work once.

Thomas

 

[GNVenom]

The problem is when the switch breaks, you could possibly push it in and turn it to toggle to MPH - but - you run the risk of breaking the trip odometer display. It's a VFD glass display and too much pressure on the reset knob flexes the board and breaks the display. There is no replacement display available and the dash would go dark on 1/3 of it. And, if your battery goes dead or needs to be replaced, you have a 50-50 chance that the display will slip back to KPH.

Not worth the risk, IMO.

John
>>

 

[buicktom61]

Hello John,

I have ordered your 199 mph processor a while ago. I will change it in the next days. Is it possible to put an extra switch for changing from miles to kilometer into the dash? The reset function works perfect.
Thomas

 

[GNVenom]

The same switch resets the trip odometer and sets the KPH/MPH option. There are four wires on the switch; two of them reset the odometer, the other two set the mode. You would need to solder a pair of wires onto the display board, then attach them to a switch.

John
>>

 

[buicktom61]

Do you know the color of the wires I need? Do I need a switch or switch which gives only a pulse?
Thomas

 

[GNVenom]

Switch is soldered to the pc board, no colored wires on it. Momentary pushbutton switch is all you need. But you will need to solder onto the PC board.
John
>>

 

[buicktom61]

Hello John,

I will do carefully.
Thomas