I was wondering when my alternator was dying why did my check guage light came on


I di replace the alternator and battery

 

Is there still a check engine light on after you replaced the alternator? Is that what you're asking?

 

its not the check engine light its the gauge light its red

 

Could be water temp, volts, or oil pressure tripping the light.

 

what gauge light is red?

 

It's only supposed to come on when one of your gauges is reaching critical high/low. I don't know related malfunctions, but it could be low/high volts; high cooler temp; high/low oil pressure, etc. It gives an audible chime so you can check your gauges in case you don't notice. I noticed a few times with oil pressure and water temp on my ram. If no gauges are critical, then I don't know. Could be a broken gauge or something.

 

Also could be a bad battery temp sensor under the battery tray.

 

I'm surprised that wouldn't trip a cel instead.