What is the current drawn by the starter motor?

What is the current drawn by the starter motor?

A good starter will normally draw 60 to 150 amps with no load on it, and up to 250 amps under load (while cranking the engine). The no-load amp draw will vary depending on the type of starter. If the amp draw is too high, the starter needs to be replaced.

What causes excessive current draw by the starter motor?

High resistance within the starter itself, worn brushes, or grounds or opens in the armature or coil windings can be cause excessive current draw. It can also result from increased internal friction due to shaft bushings that bind or an armature or magnets that are rubbing inside the starter.

How many amps does a GM starter draw?

Most GM starters are “free speed” (no load) rated for 9 volts and will draw between 50-95 amps, so elnomad and onovakind are absolutely correct in stating that the starter could draw as much or more than 200 amps depending on the load (mechanical component condition).

How much voltage should a starter draw?

You can test for proper cranking voltage with a voltmeter while—you guessed it—cranking the engine. The several hundred amperes of current the starter motor draws should pull the battery voltage down to a normal 9 to 10 volts.

How do you perform a starter current draw?

Use an ammeter/voltage meter to test the starter’s current draw.

1. Connect the test leads to the positive and negative terminals and then connect the clamp-on amp pickup around one of the battery cables.
2. Set the voltage meter to Int 18V and adjust the ammeter to read zero.

How many amps does a big block starter draw?

During steady-state cranking (engine cranking with ignition disabled) of ordinary “whatever drove through the door” vehicles using stock starters (no mini-starters) a GM big block may draw as much as 225 amps; generally a bit less than 200 amps.

What should the current draw be on a starter motor?

If you are using a separate ammeter and voltmeter instead of an electrical systems tester, the key is to observe the voltage and the amperage at the same time. The voltage should remain at or above specifications (~10 Volts) while cranking the engine. High current draw and low cranking speed indicate a faulty starter or possible engine problems.

How do you do a starter current test?

Visually inspect the starting system for any physical defects or loose connections. Perform a starter current draw test after the battery been inspected and affirmed fully charged. Bring the engine to normal operating temperature before performing this test because a cold engine requires more current than a warm engine does.

Why does my starter draw a low current?

High current draw and low cranking speed indicate a faulty starter or possible engine problems. Low cranking speed and low current draw indicate excessive resistance in the starter circuit. Slow-cranking and high current draw typically indicate worn bearings or bushings inside the starter.

What does a faulty starter motor sound like?

A faulty starter motor can sound like a flat battery, the engine turns over slowly or not at all, sometimes you can see the battery terminals and leads smoke or get hot due to the high currents been drawn by the faulty starter. First thing, check for other faults.

If you are using a separate ammeter and voltmeter instead of an electrical systems tester, the key is to observe the voltage and the amperage at the same time. The voltage should remain at or above specifications (~10 Volts) while cranking the engine. High current draw and low cranking speed indicate a faulty starter or possible engine problems.

High current draw and low cranking speed indicate a faulty starter or possible engine problems. Low cranking speed and low current draw indicate excessive resistance in the starter circuit. Slow-cranking and high current draw typically indicate worn bearings or bushings inside the starter.

Visually inspect the starting system for any physical defects or loose connections. Perform a starter current draw test after the battery been inspected and affirmed fully charged. Bring the engine to normal operating temperature before performing this test because a cold engine requires more current than a warm engine does.

How many amps does a 4 cyl starter draw?

There’s no point fusing a circuit that’s supposed to draw over 200A – especially on an antique. And no: a 92hp 4-cyl. tractor starter doesn’t draw 500A; it probably doesn’t draw 150A, and it’s still not worth fusing.