Spark to cylinder (at random)? If yes...
How is the timing?
When your car isn't starting the car you can't hear it while turning on the ignition. You're gonna have to check the battery and alternator as well before replacing a starter.
check the battery or battery cables or the alternator or starter
Usually insuffucine power to starter caused by bad or undercharged battery. Try jumping it. You might need a battery or alternator. A bad starter can also do this. Many parts store can test for free and all repair shops can test for you but might charge a few dollars.
Could be. But it might be an alternator problem instead of a batery problem. You need a good alternator to keep the bttery recharged. I wouldn't run out and buy a battery without getting the alternator checked.
Can be a dead battery, defective starter, loose or corroded battery connection, or blown main fuse. If nothing comes on when you turn on the ignition switch and your interior lights are not working it is not the starter.
So many things could be wrong and cause it to not start, but from what you have provided the next step would be to trace the cables to the starter and see if they are corroded or broken, you didn't mention if the car was turning over or not, so I assume it isnt, so if the battery has power, and the alternator isn't the cause then you need to follow the power, it goes from the battery to the ignition, then to the starter, since we know the battery is good, check to see if power is getting to the starter, if not trace the problem in between those two points.
First, make sure your all of your electrical connections and fuses are good. (battery cables are not corroded and cable to starter and ground are good) If they are good, it sounds like you either have a bad ignition switch or starter. You might try having someone turn the ignition switch to start position while using a multi-tester to see if you are getting power to the starter. If you are getting power to the starter, and it won't engage, chances are you need a new starter. If you do not have power to the starter, you might have a bad ignition switch. In certain circumstances you might try tapping on the starter with a hammer while someone is turning the ignition switch to see if it will engage. If it will, I would look to a bad starter. I have found that a majority of the time, a starter is the problem, not the ignition switch. Hope this helps.
The first place I'd start would be the battery, alternator and starter. Verify that the battery is good and that the alternator is fully charging it, and that the starter isn't drawing too much current.
there is no relay for the starter. there is a solenoid (switch) and ignition switch. the solenoid is part of the starter (small cylindrical shape above starter housing. the solenoid has the battery and ignition connections). and the ignition switch is where the car-key goes. you need at least 8v from the ignition to the solenoid for the starter to operate. use a multimeter. otherwise check your starter - battery connections. otherwise replace the starter. otherwise, take off the starter and inspect inside the starter housing. if the starter is clicking but not turning the engine the starter teeth aren't engaging with the teeth on the flywheel. get a manual to the car here: http://www.germanautoparts.com/Books/Volkswagen
Could be: Seized engine Weak battery loose or corroded battery cables Bad starter solenoid Bad starter Bad neutral or clutch safety switch
Most probably its the starter coil. That's evident if on turning the ignition key, there is a clicking sound. It may be also bad alternator with a worn out battery No fuel getting to engine or spark plugs not firing for some reason. Sorry, you have to find out which.
check the battery conections they might be loose or even the starter conections if that doesn't work charge your battery first before trying again