i replaced coolant temp sender and the sensor ...after i put sensor in the temp gauge stays all the down wont move at all.....help??????

 

Welcome to the forum

The Temp Sender is at the back of drivers side of engine, it has 1 wire connected, this is only used for the dash board temp gauge.
In 2000 the sender was 2 wires, so could be in '99 if it was made late in the year, red/white stripe wire is sender wire on 2 wire setup.
Just above this sender is the oil pressure sender

ECT Sensor has 2 wires connect, it is on the drivers side but towards the front of the engine, it is only used by the computer.


So check the sender, maybe wire came off

 

On my 98, both sensors are at the front of the engine, on the plastic thermostat housing.

I had the same problem. Replaced both sensors and the thermostat. Neither helped.

The problem was that the heater valve had been bypassed. There needs to be coolant flow through the heater hoses to keep the thermostat housing hot. Since I fixed that, the gauge stays right in the middle now.