Originally Posted by geomaster
Hey guys. I have an issue with a 2003 Trailblazer EXT LT that is overheating.
It appears to overheat when the car is idling after heavy use. When driving the temperature gauge indicates that the temperature is okay around 210degrees.
However once the car is idling after being driven around for a while, the temp gauge increases quickly. A few times it was at max and Check gauges light turned on.
At this point I could hear the coolant in the second reservoir tank boiling and the fan was barely spinning. I then shut off the engine to let it cool.
I intermittently see the Check engine light turn on and off. When on it reports code p1481 which indicates an issue with the fan clutch I believe.
Occasionally when the car is first turned on (cold start), it will have the very loud 'crop duster' sound in which the fan spins at maximum. However this stops after a minute at which the fan then idles.
Does this mean there's an issue with the fan clutch? Or is this a bigger problem? Would the water pump be causing this issue?
How else can I troubleshoot this issue (without just replacing the fan clutch)?
How do I even examine the wiring harness to the fan clutch? Do I need to remove the fan? Can I remove this without having to move the radiator?
If it does not overheat on the hi-way, overheats when driving slow or not moving and you have a fan clutch code, I'd say you need a fan clutch or your wiring is suspect.
EDIT: You can remove the connector at the fan shroud an physically look at each connection.