It could be a short on the guage pod, a blown fuse all by itself... Could also be a bad temperature sending unit (burnt out or lost contact) Could also be an ECU problem... I would have it diagnosed by the dealer or buy/find a Factory Service Manual and attempt to check the wiring via the wiring diagram in the FSM. I had my guages go dead when someone installed a new header of all things.... it was a fuse. Hope that helps a little....
Temperature gauge may drop when heater turned on because additional coolant from heater core is introduced to cooling system - usually this coolant is cooler than what is currently circulating
A short between the heater switch and temperature gauge.
Thermostat probably needs to be replaced.
I own a 95 200SX SE and it sits around cool range. Below half on the guage. I would say its either the thermostat, Rad has a plug somewhere, or the water pump is weak.
My Altima had that problem and it was the water pump going out. It started with temperature gauge was moving, but then it started leaking and finally the heater stopped being warm at idle.
The heater core is just like having another radiator, only smaller. Once you turn your heat on, and force air through the heater core with the blower motor, the engine's coolant's temperature is lowered, and circulated back to the engine, probably right where the temperature sensor is located.
Check the temperature gauge. If it is running cold, replace the thermostat.
Low coolant, check when engine is cold.
The heater core may be plugged or not flowing properly. This would not allow the water to flow properly to cool the motor. Also you may have a bad or loose ground wire to your heater switch, this will give you a false reading on the temperature gauge.
neather temp sending unit or faulty gauge....
check the wiering /our your sending unit no good
Most likely cause is a failed engine thermostat.
If this is about a car: the heater in a car is basically another radiator, but this one sitting inside the car. When you turn the heater on you draw heat from the engine and into the car. If you aren't running the car hard enough the temperature in the engine will drop.
replace temperature gauge
If you are absolutely sure you do not have air trapped in your cooling system then you may have a defective gauge if you are getting heat through your heater. Usually I would say you have a coolant flow problem with either a stuck thermostat or a bad water pump but if you have heat from your heater, then you must have circulating coolant in your system. I would check the gauge or the sensor.
If the coolant level is okay, I would suspect a restricted heater core. Try flushing the heater core.
Do you mean an oil pressure gauge? Not tach?
A common cause is the thermostat being stuck in an open position.
Fuse location for temperature gauge for a Malibu
sounds like the thermostat is sticking
Defective temperature gauge or defective temperature sensor?
Low coolant level which causes an air pocket in the engine.
It is easier and cheaper to replace the temperature sensor--try that first
The temperature gauge is broken or not calibrated. You need to have your heater or thermostat regulated and/or looked at.
Could be a failed engine coolant temperature sensor. Easy enough to replace and not too expensive.