The blower is not blowing. Check for burnt fuse or faulty switch.
The temperature sender (the sensor that sends the temperature signal to the gauge) has to be immersed in coolant in order to correctly read the temperature. If the coolant is so low that it leaves the sender high and dry, the temperature shown on the gauge will not be a true reading. if the sensor is not immersed in the coolant, there a big chance it wont read at all...
Depending on the engine, the coolant temperature in a Cadillac could be from 180 to 195 degrees. The thermostat can be changed to give a lower or higher temp reading.
The guage on the dash uses the ONE wire sensor... This is located in the block near the drivers side. Eric First check to see if you have coolant in the radiator. If there is no coolant you will not get any reading from the temperature sensor. If there is coolant then change the temperature sensor.
Head gasket. Do block test for gases in coolant
The 1999 Cadillac normal coolant temperature gauge reading should be 180 degrees. A 195 degrees thermostat could be used, causing the temperature gauge to read 195.
If you are referring to the temperature reading on the gauge, then it's possibly a bad thermostat.It will also read 'cold' until the engine has sufficiently warmed up.Lack of fluid (water and/or antifreeze) in the radiator.Low engine temperature (bad thermostat).Low coolant level.Bad gauge.Wiring issue.Coolant temperature sensor bad or not correctly grounded.Problem in an electornic control module.
Be careful there is a temperature coolant switch mounted next to the thermostat housing. I thought this was the sensor and replaced it by mistake. There is another sensor.
is the coolant temperature sensor giving a correct reading to the computer? Is the fan getting power?
take resistance reading between the leads
There are a number of things that could make the light come on including you coolant temperature sensor, very easy part to replace, check your gauges and make sure that all of yours are working and that they are reading correctly.
Because when your moving, air is moving at the radiator, cooling it down, thus cooling your coolant down, thus cooling your motor temperature down causing the coolant temperature sensor to pick up a lower reading and relaying it to the gauge. Depending on how high it is in "Park" you may have poor circulation, a broken or missing fan shroud, weak water pump impellers, low coolant, inactive coolant fans or a bad fan clutch.
If you mean that the engine fan is on at all times and that the temperature gauge is indicating that the engine is hot, even when it is cold, then the problem is your coolant temperature sensor. Your car probably has an electronic engine cooling fan,which is turned on by the vehicles computer when it is signaled by the coolant temp sensor. The coolant temp sensor also gives the reading for the dashboard gauge, and if it is reading hot at all times, then the computer thinks the engine is overheating, and is probably retarding the engine timing and cutting back on or increasing the fuel mixture(effectively ruining your gas mileage), in an attempt to save the engine.So replace the coolant temperature sensor or have the electrical circuit checked by an automotive repair professional.