i was able to email then and this is what they said and it worked i also run auto meter gauges in a custom dash since the last owner cut the dash frame part.
The gauge in your car must be sensitive to battery voltage. There are a couple solutions to this, but they both will require a recalibration - sorry.
The first way is to do the calibration while your car is running, that way the voltage will be the same as when you are driving the car. But, when the engine is turned off, it will read high.
A better solution is to turn on voltage correction on the MeterMatch. Here's the part of the manual that describes how to use it:
Voltage Correction
Most gauges are connected to a voltage regulator in the instrument wiring so that they get a constant voltage whether the engine is running or not. However, if this is not the case, when you calibrate your gauge at one voltage (for example, engine not running, battery at +12.5V), when you start the vehicle and the voltage rises (for example to +13.8V), the gauge reading might change significantly. If you run into this, MeterMatch has an automatic voltage correction feature that corrects the reading for different voltages. To enable this feature: (a) remove power from the MeterMatch, (b) set the rotary switch Ѳ to position "0" (normal operating), then (c) press and hold the Up button while applying power to the MeterMatch. Hold it for at least a second after power is applied. MeterMatch will remember this setting in future use. If you wish to remove the voltage correction feature, repeat the same process, but hold the Dn button rather than the Up button. Note that if you change this setting, the gauge will need to be recalibrated with the new setting.
If you don't mind, let me know what type of car it is, so in the future I can tell customers with a similar application that they need to turn on voltage correction.
Regards,
