How to Perform a Current Draw Test of Cars Starting System
Sponsored LinksA quick check of the entire starting system can be known by doing a starter current draw test. The herein steps outline 
a typical procedure for performing a current draw test on a starting system. The starting current draw should meet the specifications listed for the car model being tested.
First of all you should prepare the tester (Sun VAT40) as follows; set the Load Increase control to Off, connect the tester Load leads to the battery terminals (Red to positive and Black to negative), Set the V-meter to Int 18V, adjust ammeter to read zero using the electrical zero adjust control. Please note that the battery open circuit voltage should be at least 12.2 V(50% charged).
And here are How to Perform a Current Draw Test of Cars Starting System step by step guide:
1. Connect the clamp-on Amps Pickup around the battery ground cables
2. Make sure all lights and accessories are off and vehicle doors are closed
3. Disable the ignition so the engine not start during test
4. Crank the engine as you observe the tester ammeter and voltmeter (normal:200-250rpm; current draw shouldn’t exceed the maximum specified, cranking voltage should be at or above the minimum specified.
5. Restore the engine to start condition and remove tester leads
Results:
1. High current draw; low crankingspeed : indicate a faulty starter, engine problems.
2. low cranking speed, low current draw: indicates excessive resistance in starter circuit
3. So, always remember for the fully battery charged to ensure accurate results.
Completed details can be seen here (source: toyota.com)
