Porsche Repair: please help, auto parts store, starter relay

Question
HI, THANK YOU SO MUCH FOR YOU TIME AND WITH LOTS OF INFO. I WAS TRYING TO ASK IS. WHEN I START THE CAR I HEAR "CLICK" SOUND ABOUT %80 MECHENICS WOULD SAY IT'A THE STARTER (WHICH NEEDS TO BE REPLACE) & AND ABOUT %20 MECHENICS WOULD SAY IT'S THE STARTER OR THE RELAY. SO MY QUESTION IS HOW TO CHECK THE STARTER & RELAY & WHAT'S THE MINMUM VOLT I SUPPOSE TO GET ON 12 VOLT METER. I HIGHLY APRICIATED FOR YOUR TIME AND FREE SERVICE. THANK YOU AGAIN TAKE CARE.
-------------------------
Followup To
Question -
hi, how are you? first of all i like to thank you for your free service and time.
Sir my question is,
how to check starter & starter relay. (weather there is a power or no and which auto electrical voltmeter should i use to check it) can you please also suggest any website where you can learn about auto electric and electrical troubleshooting.

thank you so much!
Answer -
Hi Asif, thanks for the nice comments.  Any digital volt meter you find at your local auto parts store will do nicely in checking your starter.  The key is to be able to read voltage from 0-15 volts.  Getting a reading to tenths (like 9.8 volts) is plenty in terms of precision.   One important  feature you'll want is a continuity checker.  Usually, this is shown as an audible buzzer or a light when continuity is present.  In addition, a good meter will give a digital readout and the buzzing when continuity is found.  The readout will reflect how strong the connection is.

One day you'll likely want to measure ohms also, so if the meter you're considering provides for this, buy it.

I'm not sure exactly what you're trying to check at your starter.  But here's the basics.  The largest wire attached to the starter will always have the same voltage reading as the battery.  This means when you connect one wire of the voltmeter to the positive terminal of the battery and the other to the negative terminal, the reading "at the battery" will be 12.8 volts.  (Usually a 12 volt automotive system will have a good battery with resting voltage of 12.8.)  Measuring the "starter voltage" means touching one wire of the volt meter to the connection of that largest wire at the starter...and the other wire to either the negative terminal of the battery or to a convenient ground.  When in this position the meter will read 12.8 or whatever the battery's reading is.

The above test proves the connection from the battery to the starter is intact.  This assumes the connection of that large wire is firm and clean.  Any looseness or corrosion or greasy grime is a potential voltage issue.

I've never found an exceptional troubleshooting  website.  There are many (like this one: http://www.autohausaz.com/html/auto_electrical_systems.html) that are very helpful but not very exhaustive.  

I suspect you'll want to do other starter tests after you get your volt meter.  Write back when you're ready...and tell me what you're trying to figure out.  Thanks.  Dave

Answer
Asif,

Thanks again for the nice feedback.  The issue of starter vs. relay-plus-starter...which one is bad... usually comes down to where the relay is located.  On many Ford vehicles, for example, the relay is located far away from the starter, usually a fenderwell in the engine compartment.  It's easy to check and its the one making the clicking noise.

On many other cars the relay and the solenoid that actually activates the starting process is attached to the starter.  Harder to check.  Usually if this starter is removed to check the solenoid (and relay) it's replaced in total, because its not cost effective to replace just the solenoid.  Obviously on the cars with the remote relays, they can easily be changed without even getting greasy.

In both cases you have to be getting battery voltage, right around 12.8 for the starter to work effectively.  Sure some starters will work at a bit less, but a low battery will cause a clicking noise as well.

Let me know what you find.

Dave