Car won't start

[Slobo7x]

I'm sure you've heard it before but I'm stumped. I've been working on this 6 speed S5 for over two weeks now, replacing starter, starter cable, other items including a brand new Audi battery.

Car did "tow start" when I had it towed, so I know the engine turns over and runs.. No immobilizer issues I think.

I turn the ignition on, press the clutch and start button and nothing, no clicks no cranking. Gauge cluster just goes black and that's it. all the battery cables are tight, no problems that I can see.


Checked all the fuses and pulled starter relay out to test, clicks just fine. Starter is brand new as well. All fuses are good.

My thoughts are clutch switch or ignition switch? Any ideas would be greatly helpful, I was really looking forward to this car running after so much work.

Thank you so much

[TTRStud]

I think you're right on the money, though I'd go for the clutch switch first, here's why: if you can push start the car, that's an indication that the ignition circuit closes properly. Bad ignition circuitry would probably prevent the car from starting at all. Start with the clutch and move from there.

[JamesRS5]

Start with the very basics:

Is there a good ground on the starter and the engine?

Have you checked the ground from starter to chassis and chassis to battery negative terminal?

What are you getting at the starter motor positive connection on button press?

If you the grounds check good but you're not getting 12v at the starter, start working your way back up the starter harness to the relay, are you getting 12v at the relay on button press?

If not work up to the next point in the circuit. Just work through it logically and sequentially and you'll find it.


You said the dash lights go out on button press which would suggest the voltage is being dropped somewhere.

[Slobo7x]

I think you're right on the money, though I'd go for the clutch switch first, here's why: if you can push start the car, that's an indication that the ignition circuit closes properly. Bad ignition circuitry would probably prevent the car from starting at all. Start with the clutch and move from there.

Thank you, that's kind of what I was thinking as well. Another trip to the dealer I guess, hopefully It's not a huge PITA to replace that switch.

James, It's pretty much impossible to check contacts on the starter. I understand your logic, but it's just not doable. Starter and cables are brand new (see my other starter replacement post). Battery is brand new, connections are solid and relays/fuses are good.
The Relay is not getting 12V as it's not clicking at all, so it leads me to believe that it's a different issue.

Thank you

[shonseb]

I was thinking clutch switch until you said screen goes blank. Does your steering wheel unlock or are you able to turn on ACC? If yes then unlikely ignition switch but still possible. I wouldn't expect the screen to go blank with clutch switch. Sounds like a power draw. I would still try keeping a jumper on the battery and try to crank.

If ACC turns on, did you try running for any codes?

[Slobo7x]

I was thinking clutch switch until you said screen goes blank. Does your steering wheel unlock or are you able to turn on ACC? If yes then unlikely ignition switch but still possible. I wouldn't expect the screen to go blank with clutch switch. Sounds like a power draw. I would still try keeping a jumper on the battery and try to crank.

If ACC turns on, did you try running for any codes?

Steering wheel is unlocked, ACC is on and navigation screen is fully on. Maybe I said it wrong, it doesn't go fully blank. It's like that brief one seconds before it starts when everything turns on. It's hard to explain, but I think I'm going to go with clutch switch at this point.

My VAG cable isn't in yet, I see EPC and tire pressure lights on the dash with ignition full on.

[JamesRS5]

Did you code the battery? I'm sure I read Audi batteries need the serial numbers entering in VCDS.

[Slobo7x]

I didn't no, as I don't have the cable yet. I wouldn't think this would cause no start condition?

Audi is telling me the clutch switch comes together with master cylinder, so now I have to buy the entire assembly $250! grhh!

[NPuter]

I didn't no, as I don't have the cable yet. I wouldn't think this would cause no start condition?

Audi is telling me the clutch switch comes together with master cylinder, so now I have to buy the entire assembly $250! grhh!

Yea not coding the battery definitely wouldn't cause the car not to start

[TTRStud]

I didn't no, as I don't have the cable yet. I wouldn't think this would cause no start condition?

Audi is telling me the clutch switch comes together with master cylinder, so now I have to buy the entire assembly $250! grhh!

Audi is correct - also, now that I think about it, under prior ownership my car had the clutch switch replaced due to an intermittent start issue. Previous owner reported he had to press the clutch too hard to get it to start, and even so the car wouldn't start sometimes. Your car may be at a more advanced stage of the same issue.

[Slobo7x]

Thank you.

Is it strange that I never get a message on the display "press clutch to start the engine" ?

maybe I should try starting without the clutch pedal lol

[Slobo7x]

just an update, i just removed master cylinder from the car.. upon releasing all interior clutch components I pulled the unit out and the clutch switch complete came off the unit! As if it was already broken or off. By looking at two pieces I have no idea how it's held together.. Has to be some serious adhesive.


I will get a new unit installed tomorrow, but at least I'm hoping this is a step in right direction as this one was broken off.