from CAspers instructions
"
I N S T A L L A T I O N I N S T R U C T I O N S
103070 Bargraph Boost/Tach Module Calibration Repair Kit
This kit contains a pair of calibration IC’s for the turbo Buick-Grand National-T-Type dash mounted display module. The
module is found in the lower right hand corner of the dash cluster, opposite the fuel gage. Typically the display of the
module loses its accuracy when displaying the turbo boost pressure, engine RPM, or both. When the tach portion of the
display is out of calibration, you will see the LED bars reach full red-line well before the engine is actually at that RPM.
When the boost portion of the display goes out, typically, the LED bars will indicate boost when there is no boost present
(such as during idle). These two chips will put the display back into factory calibration and the display will then show
proper boost and engine RPM. Note that if there are any burned-out segments in the bar-graph display, they are
usually a result of display driver chip malfunction. There are five display driver IC’s in the display module. Driver chips are
available separately from Casper’s Electronics.
To perform this repair, expertise in soldering and de-soldering is a must! You must use the proper de-soldering tool to
remove the defective IC’s from the PC board found inside the bar-graph display module.
The module must be removed from the dash cluster in the following manner: First, remove the cluster trim plate by
pulling outward from the dash cluster. There are spring clips that retain the trim plate, and normally these clips tend to
stay in the sub-cluster when pulling the trim off, so if the clips are still in the rectangle holes, you can remove them
carefully with a pair of long-nosed pliers. Press the clips back on to the tabs on the trim assembly.
Next, remove the cluster lens and filler using a 7/32” nut driver. Remove the two 7/32” screws on either side of the lower
plate that holds the bar-graph display. Pull this plate forward, unplugging it from the sub-frame terminals that hold the
fuel gage in place. Using a 7mm nut driver, remove the four screws holding the blue sub-frame in place. Pull the sub-
frame forward - you will be pulling against the speedometer cable, so you should push the cable toward the dash from
under the hood to make it easier. You can then access the connector that is attached to the 16 inch harness running from
the bar-graph display. Once you un-plug this connector, the bar-graph display can be removed from the vehicle.
"if you cant pull the plug up usually just the trim plate with the ac vent under the steering column
at the extreme pull the radio
