Car will not crank when key is turned

Originally Posted by chansta

all im trying to do is help. i honestly dont believe that you used a amp clamp to measure current draw considering you specifically stated manufacturer directions on how to read parasitic draw and you also stated that you put your "ammeter" in series.

also i never said to knock on the starter motor. i said to jump the terminals to bypass solenoid and apply direct battery power to the starter. you can use a flash light and see where the terminals are from the top of the engine.

no hard feelings here best of luck to you.

Chan I really appreciate your help since I'm green on the repair dept and anxious to learn. You have given me excellent suggestions which i have applied. The knocking the starter was not suggested by you but I have done that in american cars and sometimes work.
I did connected the Ammeter in series to measure ma parasitic currents as well as the hook on. Acyually there is a diy in the net for measuring parasitic currents where i got the idea.

Did you swap with with a known good key? if possible take it to BMW technician as GS mechanic may not do it as fast, and not familiar with repair procedure

Sent from my Nexus 7 using Bimmer App

Originally Posted by klixtokw

Chan I really appreciate your help since I'm green on the repair dept and anxious to learn. You have given me excellent suggestions which i have applied. The knocking the starter was not suggested by you but I have done that in american cars and sometimes work.
I did connected the Ammeter in series to measure ma parasitic currents as well as the hook on. Acyually there is a diy in the net for measuring parasitic currents where i got the idea.

CHANSTA,
here is a link to a video that shows exactly how i connected the ammeter in series to check for parasitic currents:


Enjoy and thanks for all your help and input.

Originally Posted by klixtokw

CHANSTA,
here is a link to a video that shows exactly how i connected the ammeter in series to check for parasitic currents:


Enjoy and thanks for all your help and input.

yes i understand that but you're not testing for parasitic draw. thats for when you've got unwanted current draw draining your battery.

starter draws large amounts of amperage and if you had your meter connected in series to test for starter current draw it would have blew the fuse in ur meter.

Originally Posted by chansta

yes i understand that but you're not testing for parasitic draw. Thats for when you've got unwanted current draw draining your battery.

Starter draws large amounts of amperage and if you had your meter connected in series to test for starter current draw it would have blew the fuse in ur meter.

not necessarily if you have a meter with the proper current range. I did check for parasitic currents and also checked for the large starting current of 600 a using a hook on meter rated for 1000a.

Originally Posted by klixtokw

not necessarily if you have a meter with the proper current range. I did check for parasitic currents and also checked for the large starting current of 600 a using a hook on meter rated for 1000a.

i'd like to kno what meter ur using to test for amperage in series upwards of 100+ amps. my coworkers have DMM that are upwards of $300+ and even then they are not capable of measuring such high amperage without an amp clamp...

Originally Posted by klixtokw

not necessarily if you have a meter with the proper current range. I did check for parasitic currents and also checked for the large starting current of 600 a using a hook on meter rated for 1000a.

Just to be clear here: a typical multimeter (digital or analog) can probably handle measuring DC amperage (current) up to a few amps. The fuse inside the meter is to prevent overloading the measurement circuit which can and will blow out the electronics in the meter. Typical multimeters are used to measure current in small quantities like milliamps. To take such a measurement the meter is connected in series to the circuit. Thus this is good for testing parasitic draw, as noted. The moment you fire up anything that can draw more than a few amps, such as power window, power vert top, or headlights, BAM there goes the meter's fuse. Or it goes up in flames.

A clamp-on DC current meter (ammeter) works by sensing the magnetic field surrounding the wire when current flows through it. (Electricity 101: current flowing through a wire induces a magnetic field along the wire. Placing small coils of wire in a magnetic field produces electric current in the coils, which is measured by the meter.) The clamp on meters usually don't do milliamps very well simply because clamp-on ammeters are meant to measure big draws, not little ones. There are many factors including geography and surrounding equipment/electrical that make the clamp-on ammeter more or less useless to measure small amounts of current. Note this is not in the circuit being measured at all, neither parallel nor series. Just don't take a DC ammeter and clamp it around a 1500 volt AC transmission line

Using a clamp-on ammeter, if the current reading does not change when turning the ignition key, then a) the interlocks are preventing the circuit from closing, and/or b) the power is not being delivered to the solenoid/starter. Power delivery can be interrupted by loose wire connections and poor ground straps. At the weak points (loose connections) the temperature would go up significantly due to resistive heating, unless the resistance due to poor connections is so high that hardly any current can flow. (Witness the failed ground connection on E46 taillight assemblies; they melt because of poor connection and underrated connectors.)

I hope this background helps when learning how these tests reveal important clues.