1994 Es300 Coolant Guage Not Working

[Hazey999]

I just bought this car and noticed that the coolant guage does not work. Could this be electrical, or mechanical? The is no illumination to it either. Any way to test it? Thanks

[gbhrps]

Hazey999,

The coolant gauge is electrical. Usually when they go the problem is traced to the connector of the sending unit in the engine block or thermostat housing. Cleaning up the corrosion with a wire brush and some electrical contact cleaner spray normally does the trick. If not, next in line to check is the actual coolant temp sensor. A multi tester can check that its ohms output varies as the temperature rises in the engine. If it checks out fine, last to zero in on is the temp gauge itself, usually ending with its replacement.

As for its lighting, the bulbs that light the gauge may need to be replaced. If the gauge needle has gone out, check the thread archives here for the manner in which to replace the needle LED's. Good Luck!

[Hazey999]

Hazey999,

The coolant gauge is electrical. Usually when they go the problem is traced to the connector of the sending unit in the engine block or thermostat housing. Cleaning up the corrosion with a wire brush and some electrical contact cleaner spray normally does the trick. If not, next in line to check is the actual coolant temp sensor. A multi tester can check that its ohms output varies as the temperature rises in the engine. If it checks out fine, last to zero in on is the temp gauge itself, usually ending with its replacement.

As for its lighting, the bulbs that light the gauge may need to be replaced. If the gauge needle has gone out, check the thread archives here for the manner in which to replace the needle LED's. Good Luck!

Thanks for the quick reply. I'll track down those parts and check them out/clean them up. I don't like the idea of not knowing if the engine is overheating!