Starter motor solenoid current draw.

I know it’s been asked before but I can’t find an answer. My immobiliser will handle a max of 18A. Will the solenoid draw more than 15A?
My multi meter will only go to 5A before going pop so I can’t test it. I know the solenoid is just a relay but it has a heavy duty cable running to it in the Sierra.

Starter is from a 2L dohc sierra.

Any ideas ?

I'd guess anything up to 20 Amps?
You can work it out if your multimeter is accurate at low resistance. Then divide 12(volts) by the resistance (ohms) will give you the current.
My guess will be that it is less than 5 ohms as they are quite strong on a car starter

I have a 20A meter at home in lynn. Will be back later today if you want to borrow it to try, you are welcome to pop over tomorrow or this later this afternoon if so. You can also borrow the synchro for a while as well.

David

I don't think the solenoid alone will draw much more than 10A ...... but that is only my theory so don't take that as gospel

Answered my own question Turns out my meter is beter than I remebered.

The answer is just over 10A

Blimey! I must be cleverer than I thought!

The cable is only a thin one to the solenoid, the thick cable is to the starter after the solenoid has thrown in.

Yep it sure is Pete. But the solenoid wire is heavy duty for 10A

May not be so easy to check.

I think most starters has two solenoid windings. One for pull in, high current, and one for holding, low current.

The pull in current is then only present for a very short period, < 1s, and not so easy to messure.

Don´t know the pull in current, but would guess around 20A.

As far as I know most Ford solenoids only have the one coil (at least my Duratec has anyway) A dual winding coil system would probably require ecu control wouldn't it?

if you don't have a meter just try different size fuses and see which ones blow. Not the cheapest way but a simple work around.

No ECU needed for dual coils.

The pull in coil is disconnected internally as the solenoid reach the end position and the starter starts cranking.

Ah I see. So you might have 20A for 0.1 seconds, then 10A while the starter is turning.

Correct, but the ratio between pull in current, and hold-current would normally be bigger than 2:1. More like 4:1.