Bendy toy
Registered user
I used to be.
In the old days it hardly mattered because there was almost no electronic gear on vehicles, though it would still put excessive load on the donor generator. But radios for example were always on a circuit that switched out when the starter was engaged.
Today there is so much electronic gear its not worth the risk and the benefits are minimal. A starter can pull 100s of amps and even more if the voltage falls. Running a generator that makes 50A or 60A (max) isnt going to make much difference to the starter but the load will hammer the generator which is usually not fused to the battery.
The heavy current will cause sparks (and noise) at the starter brushes and the windings cause current surges into the electrical system. The battery should absorb most of it and stuff like engine ECU is surge protected. The sensitive stuff is switched out while the starter is engaged.
That's the issue when running the donor car engine - the sensitive stuff is all live so gets kicked by noise and spikes from the connected starter that it would normally never see.
So there is minimal benefit from running the donor engine and a good risk of of the rescued starter causing damage to the donor car. Keep the donor off at the ignition and dont crank the rescued engine for too long.
In the old days it hardly mattered because there was almost no electronic gear on vehicles, though it would still put excessive load on the donor generator. But radios for example were always on a circuit that switched out when the starter was engaged.
Today there is so much electronic gear its not worth the risk and the benefits are minimal. A starter can pull 100s of amps and even more if the voltage falls. Running a generator that makes 50A or 60A (max) isnt going to make much difference to the starter but the load will hammer the generator which is usually not fused to the battery.
The heavy current will cause sparks (and noise) at the starter brushes and the windings cause current surges into the electrical system. The battery should absorb most of it and stuff like engine ECU is surge protected. The sensitive stuff is switched out while the starter is engaged.
That's the issue when running the donor car engine - the sensitive stuff is all live so gets kicked by noise and spikes from the connected starter that it would normally never see.
So there is minimal benefit from running the donor engine and a good risk of of the rescued starter causing damage to the donor car. Keep the donor off at the ignition and dont crank the rescued engine for too long.
