Getting a 4.5V Train Running

[crhill1979]

I got an old 7722 4.5V train set for Christmas. After putting it together and scrounging up some new C batteries, I dropped them in and...nothing happens. A few questions:

-On the side of the battery tender there is a red switch. Is this an on/off switch? It doesn't work in either position.

-I cleaned off the battery contacts with rubbing alcohol, but one of the contacts has some greenish gunk on it still. Is there any way to test whether a connection is being made?

-The wire connects snugly into the battery tender, but the connection with the motor is *extremely* loose. Is this common?

Thanks.

Chris

[peterab]

-On the side of the battery tender there is a red switch. Is this an on/off switch? It doesn't work in either position.

It is an on off switch, centre is off, either direction is on but with reversed polarity from each other.

-I cleaned off the battery contacts with rubbing alcohol, but one of the contacts has some greenish gunk on it still. Is there any way to test whether a connection is being made?

The green gunk is rust, probably caused by a battery leak. You will need to completely remove this to have any hope of a good contact. A fine sandpaper may help. It can sometimes be impossible to repair this sort of damage.

-The wire connects snugly into the battery tender, but the connection with the motor is *extremely* loose. Is this common?

Some types of the plugs can be compressed, and if so wont make a firm fit anymore, gently expanding them fixes this.

Other things that might also be worth checking for;

There is a contact on the lid of the battery car (connects to the side wall of the car) which can be bent and will mean the circuit is not complete. Gently bending it back will fix it.

The contacts either end of the batteries can also be flattened so an open circuit exists. Bending should fix those too.

There is a button under the battery car which is designed to make an open circuit, it allows the signals to stop the train. Sometimes this has been pushed too hard, and will result in a permanent open circuit. Guess what the fix is?

You may be able to save yourself a bit of time by testing if the motor works without the battery box, just take one C cell between a couple of single strands of wire, with the other ends into the motor, it should turn slowly.

After that introduce more of the circuit to try and find the bit not working.

Apart from bad battery leaks I've had some success getting these working again so you should be able to get it up and running again. Good luck.

[crhill1979]

Thanks for all the advice, especially on testing the motor independent of the battery box. Will look into it when I get home tonight and post any results I have.

Chris