On unless you're pulling a heavy load and/or in the mountains. This would allow the engine to help control the vehicle speeds.
Yes
Normally the overdrive is allowed , so the overdrive OFF light does not light up When the overdrive is switched off , the overdrive OFF light will light up to let you know that the overdrive has been switched off
The overdrive is "ON" when the light is "OFF". Notice the light for the overdrive has a slash through it.
If the overdrive's off light is on that means it's off. If it is off then the overdrive is on.
Overdrive is the normally allowed position so you don't see the light on If you turn OFF the overdrive , the overdrive off light will light up or if there is a problem the overdrive off light will flash
On a 1999 Mercury Cougar : Overdrive is the normally allowed position ( it won't shift into overdrive until the speed is faster anyway ) If you find that the transmission is frequently shifting between overdrive and drive ( such as hilly roads ) then it is best to use the transaxle ( transmission ) control switch on the side of your gear shifter to shut off the overdrive ( O/D OFF will appear in your gauge cluster )
Yes. Overdrive is best used with longer trips at relatively constant high speed. City driving, with lots of stops, starts, and slow speeds is not what the overdrive is intended for.
Overdrive ON is the normal position But if you are towing something or driving in hilly country where the transmission is constantly shifting from overdrive to drive , then you want to switch the overdrive off
If the light says off then your overdrive is turned off, push the button again and the light will turn off and overdrive will be on again.
bad fuse or bad switch
The overdrive light will be off when the overdrive switch is pushed in. If the light flashes then that's a trouble shooting code.
Your vehicle has an overdrive button on the shifter maybe. When you start your vehicle, overdrive is always on. When you tow something, you want the overdrive to be off, otherwise the transmission will run hot and that will lead to bigger problems.