Lionel 2020 S-2 Turbine

Check the position of the e-unit lever, if there is one. All the way to one side breaks power to the e-unit, so the loco just sits on a siding, roundhouse stall, etc., without moving. All the way to the other side and the e-unit should buzz and operate normally. If there is no buzz in either position, or this is a leverless e-unit, there's either a broken power feed from the pick-up rollers or a burned out coil on the e-unit.

To inspect the wiring, remove the three screws on the bottom of the loco. One is in front of the leading truck, the other two are below the cab at the rear. With the screws removed, the body will lift right off so you can inspect the wiring.

If your turbine does not have an e-unit lever, it should have two miniature banana jacks mounted on the brush plate. They are visible and accessible from the back of the cab.

There should be a small banana plug on a short wire attached to one of the banana jacks.
To turn the e-unit on, the plug should be connected to the jack to which it is not attached.

To turn the e-unit off, the plug should be connected to the jack to which it is attached.

Here is a link to the first service manual page on this type of turbine. It covers both the 671 and 2020.  

Thanks guys, I'll look into both of your ideas, hopefully I can get it running again!

And make sure it's properly lubricated.  The turbines have an oil reservoir that needs to be kept filled.  And the side rods are functional, so be sure they're lubed, too.

Couldn't agree more! A little lube goes a looooooong way.

Good Luck!

I recommend against trying to fill the motor's "oil hole" with oil.

Oil is too light, and will just seep past the bearing and make a mess.

The Lionel Consumer instruction manuals advised customers to fill the motor's lubricant reservoir with Lionel lubricant, which was a grease.
(Unfortunately, over time Lionel lubricant hardens)

I prefer to directly lubricate the bearing that a located at both ends of the motor shaft housing.

Note: some early 1946 motors do not have the oil hole.

I agree. DO NOT fill that hole with oil. You can squirt a little oil down in it once in a while. Same with the gear box. Do not fill that with grease. Just make sure the armature worm gear and axle gear have grease on them. Check for old, rotted wiring and replace it. He likely has an E unit issue.

Rob