Should accessories be turned off when shutting off the car?

Ray Magliozzi
Ray Magliozzi

Dear Car Talk:

When I was learning how to drive back in the 1970s, I was told that before turning off the car, a driver should first make sure all of the accessories (wipers, radio, heater blower, rear window defroster, etc.) are turned off.

The idea was that it would be “easier” and better for the car to not have to power everything all at the same time when you next start the car. Also, if you have a weak battery, better to have it using all its juice to start the engine only, instead of all the other stuff, too.

Was that true back then? If so, is it true now? — David

RAY: It was true generations ago, David, but it’s certainly not true now.

On modern cars, all of the battery’s power is automatically directed to the starter motor when you turn the key to the crank position. Anything else that draws power is automatically shut off while the car is cranking. The car takes care of that itself. You don’t have to do it.

You can demonstrate this for yourself, David. Next time you go out to start your car, before you start it, turn the key to the “run” position (right before “crank”). Then turn on your windshield wipers.

They’ll start wiping. If you then turn the key to the “crank” position to start the engine, the wipers will momentarily stop while the car cranks, and then start moving again once the engine is running. And that’s true for every accessory.

In the really old days, you may remember that if you’re lights were on, they would dim when you cranked the engine — as the starter motor drew most of the available electric power.

So back then, it made sense to be sure to turn your lights off when you turned off the engine the night before. Of course, it made sense to turn your lights off the night before anyway, because if you didn’t, your battery would be stone-cold dead the next morning.

In any case, it makes absolutely no sense now to worry about turning off accessories when you turn off the engine. The car has that covered. The only exception is that, if you live in the great, frozen north, you should turn off your windshield wipers when you park your car outside in the winter.

That way, if you get heavy snow or freezing rain before you come back to start your car, you won’t strip your wiper transmission when the wiper arms flash-freeze to the windshield and then try to start wiping the second the car starts.

Subaru Forester issues may start with the clutch

Dear Car Talk:

We have a 2009 Subaru Forester Limited with a stick shift. We had no problems until 171,000 miles. Back in February, it began to have trouble starting. I took it to our trusted garage, and it started fine for them. The battery was replaced, and we finally told them to try a new starter. No luck.

The problem is still happening. The repair shop had it for a month, and they continued to have no problem with it. Back home, same starter problem. When trying to start it, we either hear nothing at all, or sometimes a little noise, not like it is trying to do something. When it does start, it starts immediately.

Help! — Connie

RAY: Hm. They had it for a month and couldn’t figure it out, and you want me to diagnose it through the newspaper? Have you tried Hints from Heloise?

It sounds electrical to me, Connie. Based on your description, I assume that, when it doesn’t start, there’s no current getting to your starter. The first thing I’d check would be the clutch interlock. On this car, you have to depress the clutch in order to start the car. That keeps you from driving through your garage door before you open it.

There’s a little switch connected to the clutch pedal mechanism that prevents electricity from going to the starter unless the clutch is fully depressed. That switch could be faulty. Or it could just be out of adjustment. Perhaps the big, hairy gorillas who work at the garage are stomping on the clutch so hard that they always engage the switch, but when you’re at home, you don’t push quite so hard, because you’re not an animal.

You might also check to make sure the floor mat isn’t bunched up behind the pedals. We’ve seen that interfere with the clutch interlock, too.

Next time it doesn’t start, while you’re holding the key to the start position, try really mashing down the clutch pedal, and see if you can break through those shag carpet disco floor mats you bought in the ’70s. Maybe buy a pair of size 12, steel toed hiking boots first.

If that doesn’t help, I would guess that there’s another connection that’s failing intermittently. So when it won’t start, while you hold the key to the start position, have someone else jiggle all of the relevant wires under the hood, one connection at a time.

Start at the battery and check both cables. Then try the cable at the starter that comes from the battery. Then the ground connection from the negative terminal. If you can get the car to start while jiggling a wire or moving a connector, you’ve found your problem.

Finally, I know they replaced the starter, but if they put in a rebuilt rather than a new starter, it’s possible you got another bad starter. But not very likely.

I think the clutch interlock is the most likely problem, and that’s certainly where I’d start. Good luck, Connie.

Got a question about cars? Write to Car Talk write to Ray in care of King Features, 628 Virginia Drive, Orlando, FL 32803, or email by visiting the Car Talk website at www.cartalk.com.

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