how to check a starter motors external wiring for volt drop

[aaronsmart]

a breif explination would help from any mechanics out there?!

[Brianmoooore]

Connect a volt meter across the two ends of the cable you want to check.

[Speedtouch]

Most starter motors have a separate solenoid (effectively a large relay), with a thick permanent live feed (+12V) from the battery, a smaller terminal coming from the ignition switch (switched +12V when you turn the key) and another large terminal going from the solenoid into the starter motor.

So, when you turn the key, the starter solenoid closes the terminals which switches the main feed to the starter motor.

[GeoffBob]

Given the magnitude of the current your starter draws, a 0.5V to 1.0V drop along your positive supply (the big fat red wire from the battery to the starter) would be considered quite normal.

Furthermore, check the earth strap that connects your engine to "chassis" and ultimately back to the negative terminal of the battery. If your earth strap is loose/faulty your starter-motor will not be able to draw the required current to crank your motor properly.

Lastly, measure your battery voltage while cranking the starter. Shouldn't drop below 9V on a reasonably healthy/charged battery (dependent upon current draw) during cranking. If it does, it likely indicates a flat or dead battery.

[Brianmoooore]

OP hasn't actually claimed to have a problem!

[GeoffBob]

All useful information that the OP can do with as he wishes Brian. And quite frankly, when it comes to my posts, MYOB.

[Brianmoooore]

As a team member on here, ALL posts are my business!
So far I'm the only one that has answered the OP's question.

[GeoffBob]

As a team member on here, ALL posts are my business!
So far I'm the only one that has answered the OP's question.

Good for you Brian.

Why the fact that I offered a little pre-emptive information should get up your nose I do not know. I was only trying to be helpful.