starter motor solenoid.

[Aussie John]

Just measured the solenoid coil resistance at about 1 ohm; I am surprised that the solenoid current is about 12 amps. If this is right then it's no wonder ignition switches and immobiliser relays have problems.
Any thoughts?

[pwd95]

Just talking about this in the Chimp cage.

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

[Aussie John]

Thanks Wyn! cheers.

[Loubaruch]

John , did you actually measure the current through the solonoid as 12 amps or deduce it from the resistance of 1 Ohm?

The solonoid has inductance so will tend to reduce the current below that calculated from its resistance alone.

Being interested I measured the current through my starter solonoid at 4 amps peak. As you rightly say this is still far too much to be passing through tiddly immobiliser relay contacts but I would expect around this level through the solonoid as it has a fair bit of work to do.

[Aussie John]

You are right Paul, I will do a measurement, thanks for the photos and info.. cheers, John.

[David Beer]

Standard wiring would be around 6 amps, it should be 12, that's the drop in the wiring and why the relay should be in the circuit to cure the hot start problem.