Q: I have a 2011 Honda Odyssey with a little more than 100,000 miles. Occasionally, if I go through a puddle, the car momentarily stalls and the "check battery/charging system" prompt shows on the dash. After a few seconds it goes away, and the car runs fine. Needless to say, my mechanic, who is excellent, is stumped. Any ideas?

A: It may be that the engine isn’t stalling but the main drive belt stops turning, and you are losing the power steering and the alternator isn’t charging the battery, which turns the battery light on.

The cause could be a faulty harmonic balancer (crankshaft pulley). This part is made up of two sections with a rubber insulator between the pieces. When this gets wet enough, the inner portion on the pulley turns and outer portion slips, causing the belt to not turn.

A simple way to check for this failure is simply to pour water on the pulley when the engine is running. If it is the pulley, you may also want to replace the drive belt.

In addition — usually at about 110,000 miles — the timing belt is replaced.

Combining all of these items will add to the cost, but it is ultimately cheaper than doing each repair one at a time. 

Q: I would like to get rid of a Ford Model T Truck. Do you have any suggestions about who might be interested?

A: The Ford Model T, or Model TT, is still collectible, but because so many were made, they're not as valuable as some other 100-year-old vehicles.

I would start by contacting the Ford Model T Club of America, www.mtfca.com, to gauge interest and perhaps get a value of your vehicle.

As for listing it for sale, Hemmings Motor News is a great place to start.

Q: AAA charged my battery, and now the radio doesn’t work. I Googled it and found it confusing, so I’m writing to you. How can it be fixed? I don’t know the radio code.

A: The problem with the radio wasn’t actually caused by the jumpstart or battery charge, but rather that the battery became completely discharged. On some vehicles, when the power is removed the radio will go into an antitheft mode, and a code must be entered to reactivate it.

If you don’t have the code, it can usually be found by cross-referencing the radio serial number. Once you have the serial number, the dealer should be able to get the code (usually for a fee). 

Q: I have a 2011 Nissan Frontier. I recently noticed that the engine fan is running constantly now. 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 — as in 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, the relays (there are two) wiring or the 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. 

Q: My 2007 Mercedes E350 doesn't always start on the first try. It happens on occasion. However, I now have a problem with not being able to fill the gas tank.

I bought the car new and have always filled the tank to about ¾ full. About two months ago, the gas attendant filled the tank to capacity. When I started the car the next day, there was a strong smell of gas fumes. Since then, each time I get gas, the gauge does not register ¾ full. Yesterday, the car would only take just under ¾ of a tank. 

A: From your description, the issue may be a faulty evaporative emission purge valve.

The purge valve is designed to allow gasoline vapors to be burned rather than escaping into the air. The purge valve, when malfunctioning, can make the gas tank hard to fill. 

After refueling it can also make the engine hard to start (flooded), due to fuel being forced into the engine. 

John Paul is the AAA Northeast Car Doctor. He has more than 40 years of experience in the automobile industry and is an ASE-Certified Master Technician. Write to John Paul, The Car Doctor, at 110 Royal Little Drive, Providence, RI 02904. Or email jpaul@aaanortheast.com and put “Car Doctor” in the subject field. Follow him on Twitter @johnfpaul or on Facebook.