Installing Aftermarket Temperature Gauge

I have a 94 Ram 1500 with a 318. My gauges got messed up from taking the needles off to replace the gauge faces. I bought a cheap electronic temp gauge so that I can reset the original gauge. Would it be possible to splice in the aftermarket gauge under the dash so both the original and aftermarket are working at the same time? If not which sensor in the water pump should I install the aftermarket gauge in? There's two places I saw where it could be done but both had a sensor in them already and I want the original gauge and aftermarket to work at the same time.

Also an unrelated question. My Low Wash light has been on for a couple weeks but the windshield washer fluid is full. There didn't seem to be anything wrong with the sensor on the washer fluid reservoir that I could see.

Any help would be great. Thanks!

No one knows? What would be the easiest way of finding out if it can be done or not?