2nd Gen Non-Engine/Transmission Troubleshooting transmission temp gauge?

[Turbo Terry]

I have a Westach 300 degree gauge with the probe in a Maghytech transmission pan. It has worked fine but now upon accelleration it drops to zero but at idle it works fine. Is this a gauge problem ,probe problem or bad connection in the wiring. Please give me your best guess. Thanks

 

[SSolderitch]

Check the grounds. All gauges like the ground wire attached close to were the sensor (probe) is located and not run thru the body, frame or moror/transmission.