2.7l Dodge Magnum Overheating

This is my vehicle that I let my fiancé drive since my other car is a 02′ Celica GTS with the six speed. She won’t touch a manual…

Problem: The car overheated twice on a hot day in traffic.

This happened about a month or two ago, it’s been parked since. I finally had time today to diagnose it.

I decided to see if I can overheat it. So I check for leaks and start it up. I let it idle up to temp and then rev it at 2500rpms. The temp gradually rises and I push it to 3000. It rises some more, but doesn’t overheat.

I check again for leaks, including the cardboard I put under it and find nothing. Okay. I’m doing this in a long yard so I simulate heavy traffic conditions. Speed forward and stop, back up and repeat. Still no overheat. I get out and notice the radiator fan isn’t running. BINGO! After all that it should be running by now.

I hop on Prodemand and look up the wiring. One fuse and three relays. I check the always hot side with my test light it goes off. I check the cartridge fuse for continuity and it’s good. So next in line is the primary relay. It has power at the 30 and 85 terminals like it should. So I jump 30 and 87, BAM, the fan starts running. Bad relay.

I confirmed it by switching the radiator fan control relay with the auto engine shut down relay, same relay type. Ran the car as mentioned above and the fan came on.

Note: the car will not start without a relay in the Auto Engine Shut Down spot.

Its took about a half hour to forty five minutes to do all this. Victory felt nice.