Making Sense Of Wiring In A Home Made Child’s Toy Car

I did but not well enough, I guess. So I cleaned all the terminals as thoroughly as I could, and ran all 16 of the tests again. The only readings I found were as follows: In Lever position 2: There was a reading between terminals 1b and 2            and between terminals 3 and 4 In Lever position 4: There was a reading between terminals 1a and 3         and between terminals 2 and 4 No other terminals showed any connections in any of the four lever positions. To help me understand it, I did another wee diagram which I'll post in case it helps. The lever positions show with the forward/reverse positions as I remember them when the car worked. Thanks again for your help. I really appreciate it.

That is enough data. I will look at it tonight.

2 to one motor wire. 3 to the other motor Power to 1a and 1b that explains the jumper. Ground to 4. If it goes backwards when in forward and goes forward when in reverse, simply reverse the 2 motor wires.

Thank you for your help. I do appreciate it. T4 is already occupied by a wire from the solenoid (which is live when the on/off switch is activated). I ran wires as per the diagram below, with the For/Rev switch in Position 2 and it drove the motor forward. When I moved the lever to Position 4, and connected T3 to the motor (wire c) it also drove the motor forward.

4 to power 1a and 1b both get ground. 2 to one wire of the motor 3 to the other wire of the motor.

Bingo! - as we (used to) say in the UK. It's works as it did back in the old days. If you lived near here,I'd buy you a pint .. best I can do is send you a picture of one. Thank you so much for your help.

Okay - here's the thing: The motor works and the car drives along pretty nicely. The only thing is that the motor gets very hot. The battery loses punch after about half an hour (which is fine as it's just a toy for the grandkids) but I suspect it would last longer in a wheelchair. Do I need something in the circuit to stop the motor heating up or do I just live with it?

If you are using a wheelchair motor, different gear reduction may be in order. How fast does this thing go? If you raise the wheels off the ground and run the motor without a load on it, does it still get hot?

Thanks for the reply. It goes at walking pace - say 3.5 mph? When I first got it working, it was too fast, and the chain kept coming off. IO increased the size of the sprocket on the motor to slow it down a bit, and got the alignment right and it worked fine. It was only when I was putting it away that I noticed the heat in the motor casing. I'll put it on blocks and run it for a while and report back. John

Increasing the size of the sprocket on the motor should have made it go faster. If that did slow it down it is putting that motor in a bind. A smaller drive sprocket should slow it down and make it much easier on the motor.