Join Date: Mar 2001
Location: Peoples Republic of Vermont
Yes, The second test is the big lug on the forward facing side of the solenoid.
Yes, tasks #6 and 7...as well as all the other tasks need to be done with the starter cranking.
To do a voltage drop test the circuit must be complete. If you had the proper equipment, you could use a carbon pile to load the circuit with amperage equal to the starter motor but for lack of a few hundred bucks of test equipment..... just pull the wire off the coil+ so the ignition is "cold" and watch your fingers with the belts and fan.
If you were to check the charging system for voltage drop you'd do it similarly, but load the system by turning on the lights, heater, etc.
So, why do we do voltage drop tests instead of just checking with our ohmmeter? Because with our multimeters, which are powered with (typically) a 9V battery you can check the resistance of a component to see its nominal value.... take something simple, like our car's 1.5 ohm resistance wire. If we put our ohmmeter on the ends of the wire it will read 1.5 ohms. If we feed it 12V when the points close and complete the circuit, 8 amps will flow through until the points open. The wiring in the circuit, and the resistance wire, itself, are capable of handling that 8 amp load.
Now, let's think about a battery cable. It has multiple strands of copper twisted together and covered with an insulating jacket. If ALL the strands, except one, were corroded and broken, if we put our ohmmeter on each end of the cable, it will read low resistance because that one remaining strand of copper wire is more than adequate to carry the multimeter's load and there is no other resistance in the wire. However, if we send 12V through the cable and add, to the circuit, the load of a starter motor, our amperage requirement of 150+ amps can not be carried by that small wire and it will fry.
What, me worry?
- Alfred E. Neuman