How many amps does a starter motor draw?
Simply so, how many amps does a diesel starter motor draw?
Diesel engines have a very high compression ratio e.g. 22:1 and require more powerfull starter motors. On average they draw between 300 and 500 Amps for average sized car engines 2 to 3 litre while on truck engines the current could easily reach 1000 Amps at initial turn over.
One may also ask, what causes a starter to draw too many amps?
If the amp draw is excessive, according to the manufactures specifications, then the starter motor is faulty. Slow cranking or high current draw can also indicate that bushings are worn because of an off-center armature. An engine in poor condition could cause the starter to work harder or longer.
Your starter motor is based on wattage (volts multiplied by amps). At 12 volts, your engine will require roughly 200 amps. So if you have a battery with 300 cranking amps, it should start any gas automobile.