There are two different eddy sensors that frequently need adjustment for Ted, but that isn't your problem.
Open the playfield lift it up, look where Ted's mouth is. There is a metal ramp, and on that metal ramp is a black microswitch. Something is wrong here, I suspect that there is trash in this area, keeping the switch from activating, but it could be a broken wire to the black microswitch.
Go to switch test, Switch Edges, lift the playfield. You'll probably want to use the yellow clippy thing on the interlock switch on the inside of the front door, but I'm not sure you HAVE to for this switch test.
Whenever you activate a switch you should hear a ding noise. From the bottom of the playfield, check to make sure you can pull the switch activator toward you and that the game responds with a ding sound. The activator could need adjustment so that a ball rolling on the wire inside the trough will cause the switch to reliably activate.
I would get a ball in my hand. On the front of the playfield, in front of the dozer, wave the ball (roll it) on the top of the playfield. With the playfield raised you can see an LED activate on the eddy sensor board. There is a small adjustment for a tiny screwdriver on these boards. The LED should be off, then activate when the ball gets close. These boards need frequent adjustment.
Now, there is a second eddy sensor, and the idea is that if a ball is trapped in front of Ted's mouth, but inside the bulldozer blade, this sensor will activate. Wave the ball (roll it) on the playfield inside the bulldozer area and the other eddy sensor board's LED should light. Adjust sensitivity with a small screwdriver if necessary.
That's where you'll need to look for this problem.
Good luck!