Temp Gauge Is Off/ Charging Prob Options

[noodleofdoom]

I just swapped a 5sfe from a 91 gt parts car. Before i started all gauges worked fine in the parts car. but now that its in my 92 st the temp gages isn't working rite. i changed all the wiring between the engine and instrument cluster (Had to remove half the interior to do so) The gauge rest at the bottom of the last cold line when power is off but as soon as the key is turned to on it will sit on the middle between hot and cold. i unplugged the temperature sending sensor and it dropped so i replaced the sensor and made sure no air was trapped in the lines. but I'm still having the same problem and still getting the code 22 from the ECM.

Also i don't know if this has anything to do with it but this is the other problem I'm working on. i charge the battery hook it up and run the car but after about 15 to 30 minuets the my full charge is almost dead. the battery warning light turns of when the i turn the motor over and stays off till about 5 minutes after you can tell the motor is running ruffly and all the lights are dim. The alternator worked fine before the swap. I have yet got the chance to check the output but i didn't get any code from the ECM about a problem in the charging circuit.

Any one have this problem or ideas. Any help would be great.