Controlling 12 V, 70 A motor(s) with an Arduino Mega (or Nano) and a 4-terminal automotive relay

Question

Components I have:

• Relay (rated at 12 V, 70 A, can't find how much current is needed to saturate its coils). Schematic here
• Arduino Mega and Nano
• 12 V Powerwheels battery + AA battery packs
• Motor: 00968-9015
• Transistor: PN2222
• Diode: 1N4007
• Appropriate wire, terminals, crimper, etc.

I need help wiring the setup in the title. I am trying to control a DC motor taken from a Powerwheels Jeep Wrangler through the pins of an Arduino.

The motor draws 70 A under normal load, and is brushed. I've been doing a lot of research online trying to understand how this would work, but I haven't found anything exactly like mine and do not quite understand how it should work. Namely, how do I connect the Arduino, transistor, diode, and battery to the relay that I have?

I should be fine with the code, like setting the pins to HIGH, it's just the wiring that is troubling me. I also am not sure if I will be able to reverse the motors' rotation with this (without an H-bridge or an expensive motor controller). Any help would be much appreciated.

Here are some resources I have been looking at:

http://henrysbench.capnfatz.com/henrys-bench/arduino-output-devices/tip122-arduino-relay-tutorial/

https://www.element14.com/community/thread/38334/l/car-relays-to-use-in-projects?displayFullThread=true

http://www.bcae1.com/relays.htm

https://itp.nyu.edu/physcomp/labs/motors-and-transistors/using-a-transistor-to-control-high-current-loads-with-an-arduino/

Here is where I got the figure for the motor's current draw.

Here is the Jeep Wrangler toy.

Answer 1

The relay information given indicates that is is intended to control a blower motor. A relay like that, as used in a car, may have its own fuse. If you can identify the blower motor fuse in one of the vehicles that the relay can be used in, that would tell you the maximum current required to drive the relay.

You might find a seller that sells it for general use. Such a seller may give more complete specifications rather than a list of compatible vehicle applications. Some sellers show a photos of their products that have sufficient detail to read the manufacturer's information printed on the product. From that you may be able to find more complete specifications.

A relay that is intended for starting and stopping a dc motor should be able to withstand the arcing. The motor should be able to withstand full-voltage starting if it is a motor that is sold for a use in which that is the normal starting mode. If full-voltage starting in your application produces an unacceptable jerk, you could make a reduced-voltage starting circuit using one or two series resistors that are shorted out as the motor accelerates. That may or may not be less trouble and expense than using an electronic speed controller.