My truck’s engine fan won’t stop running

How To

John Paul, AAA Northeast’s Car Doctor, answers a question from a reader whose 2011 pickup truck has a fan that never quits.

Q.The engine fan in my 2011 Nissan Frontier is running constantly. It used to kick on when needed for cooling and air conditioning purposes. As I’m pretty sure that they are all electric now, where is the switch or sensor located? I would assume that when it becomes defective, it would go to default mode and just stay on as opposed to dangerously not running at all.

A.The fan in your Nissan and many other vehicles has multiple speeds. The computer controls the fan speed based on information from the temperature sensor. Unlike some other vehicles that use a separate temperature sensor for the fan and one for the computer, Nissan only lists one sensor. The sensor, relays (there are two), wiring, or fan itself could be the problem. A technician with a scan tool will be able to read the temperature data as well as command the fan to turn on and off. This will help verify which components are working.Â

Q.I am tired of being blinded by headlights. I have been driving for 50 years and these new cars have headlights that are just too bright. What can be done about this? They should be illegal.Â

A.It is interesting that most of the complaints I get about bright headlights are from the people who can benefit most from being able to see better at night. At 60 years of age, we need three times as much light to see as when we were 20. I have evaluated thousands of vehicles in the past 40 years, and there are certainly good and bad headlight designs. In addition to glare, our eyes are drawn to the brighter light, so when we see a brighter headlight, we tend to stare at it. Just like needing more light to see as we age, we also need more time to adjust to the glare. Back prior to 1980 or so, most cars had standard incandescent headlights, then cars switched to halogen lamps, and people complained. The issue was solved quickly, since halogen headlights were relatively inexpensive, and many drivers upgraded to halogens. Then brighter Zenon or HID lights started showing up. These were a very expensive option in luxury cars. Now HID lights are being replaced with LED lights and that is part of the problem. Many drivers buy aftermarket LED replacement bulbs, and these bulbs can be very bright and not legal for on road use – but people buy them. Recently the 40-year-old headlight rules were updated by DOT/NHTSA to allow European-style headlights. One design is the Matrix light, I have seen/tested these in an Audi. There are 13 bulbs on each side of the car and no traditional high/low beam. These lights provide incredible light but shut down bulb/light segments as other vehicles approach. This design provides sufficient light to the edge of the road and doesn’t blind oncoming drivers.Â

Q.I recently saw a Tesla-powered Toyota RAV4 for sale. The car was older, but it said it had a Tesla drivetrain. When did that happen?Â

A.I suspect what you may have seen was a RAV4 with a very early Tesla battery (made by Panasonic). I remember seeing these at one of the big auto shows around 2010, and at the time most people just thought EVs were a fad and that Tesla was going to be nothing more than a quick mention in the automotive history books.Â

Q.What things do I need to check or go through to get my car ready for summer? After staying home for three years due to COVID, it is time to go explore our country. It will be my wife and me as well as our small dog in our 2018 Honda CR-V. The car seems in good shape and only has 40,000 miles. Â

A.Being a 2018 model still makes your Honda sound new, but it is six years old, and a little maintenance and repair may be necessary. With 40,000 miles on the car, it could need new tires (a great investment for a long road trip) and the brakes could be nearing the end of their useful life. Change the engine oil, air and cabin filters, check the battery (if it’s original, just replace it). Check all of the belts, hoses, and coolant level and condition. If the brakes need replacement, also replace the brake fluid. If you are driving with a rooftop carrier and also driving mountain roads, change the transmission fluid before your trip and use only Honda fluid. Enjoy your trip and send photos.Â

John Paul is AAA Northeast’s Car Doctor. He has over 40 years of experience in the automotive business and is an ASE-certified master technician. E-mail your Car Doctor question to[email protected]. Listen to the Car Doctor podcast atjohnfpaul.podbean.com.