This morning, I replaced the battery in my 2003 Blazer. After replacing the battery, the temperature gauge does not work, all the other gauges work. When I start the car, the temperature comes up to what I assume is the temperature of the radiator, approximately 200 degrees. After approximately 5-10 seconds the gauge drops to 100 degrees and stays there. Any insight on what the problem may be or a schematic of the electrical system for this area would be helpful.

 

Could possibly be the temp sensor? A stuck open Thermostat would cause the temp to stay so low as well. When was the last time the coolant was flushed? If you let it run for a long period of time does the gauge eventually come back up? Improper anti freeze to water ratio could cause it to stay cooler for a longer period of time. Which would make sense if it heats to around 200 then the thermostat opens allowing the coolant to circulate which would be why the temp drops so dramatically.
Hopefully this helps.

 

Thanks for the quick response.
Let me clarify the issue.The temp gauge was working fine ,until i changed the battery.
I beleive that the battery was just a coincidence.What the gauge would do is,stay at 100 like there was no power to it.I'm in florida its definitly warmer than 100.After shutting off the engine for 10 to 15 min.when i would restart the engine the gauge would come up to approx 210.which is were it normally stays during driving.After about 5 to 10 seconds it would suddenly drop to 100 like it lost power.It would stay there no matter how far or long the engine ran.When i shut it of and let it set it would do the 210 to 100 again.
Today when i Ran the car the gauge worked fine.I guess my concern is, do i have an electrical issue that is some how grounding the temp gauge circuit intermittently,or is this just some sort of fluke. Is it possible that changing the battery caused something to reset?

 

I would think that if it stays low then when you shut off and turn back that it could be the sensor im not sure on how the wiring works on the gauge but maybe pull the cluster out and look at the connection(s) to see if they all are plugged in and not loose.Also look at the sensor to see if it is just a loose connection.
Its always a weird feeling when you replace a part and then things seem to go bad.makes you wonder why but is typically not related.Wiring is expensive to get taken care of so start with some easy stuff that is free.
And go from there.
Hopefully this helps.
Let me know what happens

 

All the connections are tight for everything i think are related to the temp gauge. It is working now. Is there any way to get a schematic for the temp gauge circuit,incase it decides to freak out again?