The low coolant sending unit is integral to the coolant reservoir. I just called two dealers, they were both $117 for the reservoir(!!). Before replacing, try cleaning the contacts on the connector, and also try cleaning the sensor in the reservoir with a long bursh before spending that much money.
It is located under the coolant reservoir. You can't just replace the sensor. The whole coolant reservoir must be replace. It's a simply 10 minute job.
It cost me $185.00. That includes $85 for new reservoir tank and coolant & $100 labor.
NOTE: this answer is describing the location of the engine coolant temperature sensor - NOT the coolant sensor in the reservoir that warns when the level gets too low.The coolant temperature sensor is located directly adjacent to the thermostat housing. The thermostat housing is what the upper radiator hose (toward the right side of the engine compartment) connects to. You do not have to replace the reservoir to replace this part, but leaky coolant reservoirs are a common problem on this model.
Add coolant to the reservoir. If the low coolant light still stays on, replace the low coolant sensor.
A 1966 Grand Prix did not come with a reservoir tank. You can add one though.
Replace the reservoir with a new or used one.
Start by taking the top off of the coolant overflow reservoir. To bleed the system, run the 1998 VW 2.0 Beetle about 10 minutes, then check the coolant level. Add coolant if needed, then replace the reservoir top.
After you have completed work on the cooling system and you begin to replace the coolant, open the bleeder a couple turns. As you pour coolant into the reservoir air trapped will escape out the bleeder. As soon as you see coolant come out of the bleeder close the bleeder valve and continue to add coolant to the reservoir until you have reached the full mark. Replace cap on reservoir. Allow vehicle to run through a drive cycle and cool down. Top off reservoir to full mark if necessary.
take it to a dealer or a junk yard that does repairs
Simply fill the reservoir if it does not turn off you may need to replace the sensor that goes in it!
The coolant level sensor is located in the coolant reservoir tank. It should just screw or press in. Unplug it, remove it and put a new one in.
Check the sensor located at the bottom of the reservoir.