A few years ago my temperature gauge maxed out into the red on my 2001 Jeep Grand Cherokee. I immediately pulled into a Goodyear service center. I paid them $75 to diagnose the problem and was told that my radiator fan motor wasn't working.
I received an estimate of over $1,200.00 because they told me that I had to buy a whole new radiator fan unit because you couldn't buy just the motor. And I was told that to replace it would entail taking off the bumper, removing the front end of the car, etc. Which was why it was soooo expensive to fix.
I didn't have that much money so I drove home (turning off engine at every stop) and did some testing myself. I ran a wire directly from positive terminal of my batter to the fan motor's positive lead and guess what? The fan worked. The experts that charged me $75.00 to diagnose the problem were wrong.
So I installed a switch between my battery and the fan's motor and when I drove the Jeep I would just switch the fan on. Not the best solution, but it worked until I could solve the real problem.
I also pulled out my repair manual for my Jeep and found that the fan's housing unit can be pulled straight out by removing just a couple of bolts.
I went back to Goodyear and got my $75 back.
After some research and eliminating various causes I found out that the problem was probably the fan relay. I didn't want to cut through the plastic behind the headlight if I could help it so I found a local mechanic that replaced the relay for $50 plus parts (around $50 more).
I told him that I had read you could cut through the plastic and I didn't want that done. He told me that he could reach behind the housing (because he had small hands) and didn't have to remove the bumper. He said it was still a big chore, and I thought $50 was a bargain. Especially compared to the $1,200.00 estimate I had received earlier.
I used him 3 more times over the next 3 years because the relay was going out about once a year.
Then yesterday it happened again so I decided to bite the bullet and cut through the plastic and replace it myself. I brought out my Dremel tool and pulled out the passenger headlight and guess what? There was big hole already cut exposing the fan's relay. The mechanic that had been doing what I thought was an amazing job had lied to me about the way he was replacing the relay.
So now I can easily replace it myself AND I'm going to save my receipt because the fan relay has a lifetime warranty. Now instead of paying $100 a year, I can do it myself in 5 minutes for free.