2006 Saturn Ion Repair Question
Saturn Ion Engine Problem
The system can be broken down into three parts. By jumping the relay to make the fan run, you proved the high-current part with the fan motor is okay, however, there may be two fans or it may have four wires for a low-speed circuit and a high-speed circuit. Check if you have two different relays first, then look for a second fan in front of the radiator. Next, look on the engine, usually near where the upper radiator hose connects, for the temperature sensors. If you find one with a single wire, that will be for the dash gauge. Look for one with two wires. That one is for the Engine Computer. I'm sorry that I am more familiar with how Chrysler products do this, but check that the connector is on tight and the terminals aren't spread apart and making poor contact. On Chryslers, if that plug is disconnected while the ignition switch is on, the fan will turn on as a safety because the computer won't know when or if the engine is overheating. I DO know that on some cars the fan will not turn on when that plug is off or loose.
The next thing would be to use a scanner to command the Engine Computer to cycle the fan relay on and off so you can hear or feel it clicking. If it does, you know the computer has control of it. At that point the fan should be running too. If it is not, replace the relay. The contacts could have been overheated before the fuse blew. If the fan does run, then look at the temperature being reported to the computer. It should be turning the fan relay on by no more than 210 degrees.
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