Battery Discharging

I have a 2001 Ford Taurus and I am having a problem with the electrical system. 3.0L V6 OHV engine

Somewhere there is something dropping the running voltage down to 9.6V (approx). (Also the battery won't rechrage and the whole elctrical system dies on me on the road)

I have had the battery changed & the alternator tested good ( on new machine at advanced auto)

Doing some reading I came across some solutions, however I need to know

1) How to electrically test the solenoid

2) How to test the TRS (Transmission Range Sensor)

Any help would be greatly appreciated.

What do you mean by "...dropping the running voltage down to 9.6V (approx)?" Are you saying you are only seeing 9.6 V while the engine is running? If so, you almost must have a bad cell or two in the battery and your alternator is not working properly. I don't put a lot of faith in the battery and charging system testers at the parts stores. A friend had his tested at a parts store and they said everything was fine. However, when the car was running, the alternator was keeping the system at 14.4 Vdc with no AC noise (using an oscilloscope to check for ripple), but while cranking the engine, the battery voltage would drop down the 8.9V. We monitored the current drain on the battery with the engine and key off, and there was around 70 mA draw. He specifically asked the parts store to load test the battery. We bought a new battery for the car and he hasn't had a problem since. That was about 8 months ago.

Do you have a current meter? How about a test light? Check the current drain on the battery and see what you have with the key off, doors closed, etc.

-Rod