Car won't crank? single click

[pimpinb5a4]

B5 A4 1.8t 1999.5 Auto Quattro

So one morning I start my car fine drive to a friends house, hop in his car leave for 4 hours come back try to start my car and I get nothing.

The dash lights come on, I get perfectly good voltage on the battery and turn the key to start position and the fuel pump primes I hear a single faint click but that's it! it doesn't even try to crank.
I have Researched for hours on what it could be a no one quite has the same problem. I took the starter off all connections were good and clean, went and got it tested it passed, bought a new one anyways installed it and I still get nothing. Bought a new battery still nothing, so I looked all over the forums and tried starting in every gear neutral and park and got nothing. I took the old neutral safety switch off and it looked ok but I ordered a new one which should get here tomorrow. So I am Hoping this is the problem but I don't have high hopes. I will also buy a new ignition switch tomorrow but I don't think this is the problem because I have never had a problem with the key turning and all the dash lights and accessories come on. So I was wondering if anyone has had the same problem or has any ideas. I really need my car back!!

thanks for the help,
Cade Smith

[walky_talky20]

Holy parts purchases Batman!

Exhibit A: You took your starter to get tested. They applied 3 things:
- Ground to the case
- 12v+ to the motor
- 12v+ to the solenoid

Assuming your engine actually turns and isn't seized up (might be good to check that), all you need to do is figure out which of those 3 your starter is missing.

Chase your problem backwards from symptom to source. Begin at the starter motor: determine what you are missing, then trace it back to wherever that "what" should come from. Use a diagram. The starter circuit on these B5's is exceedingly simple.

Side note: Those transmission switches are very expensive, and not altogether easy to replace. You can just bypass them for testing, no need to replace just to hope that fixes it.

Side note #2: In a pinch where you need jo' B5 to start up like RIGHT MEOW (and you don't have time to monkey with jacking up the car and testing crap at the starter location) your best point of attack is the starter relay (aka Park/Neutral Position Relay):

Yank it out. Use a test light to make sure you are getting 12v+ from the key's "START" position. Install a jumper wire to send said 12v+ directly to the starter solenoid. You've now bypassed every piece of safety junk in between the key and the starter. Assuming the starter and the wires to it are good and connected, she'll crank. If you didn't get 12v+ from the key, the ignition switch is bad. Improvise: touch the wire to the 30 post to get some juice to the solenoid. Congrats, you just hot-wired your B5. Now drive it like you stole it.

[S_Line_A4]

It could a bad camshaft position sensor

[walky_talky20]

Nope. Camshaft sensor won't inhibit cranking. And it will still actually start and run with a bad cam sensor, might take a few tries, though.

[pimpinb5a4]

Thanks Walk_talky20 I really appreciate it. I already took apart everything to remove the neutral safety switch and removed it so its sitting in the garage waiting for the new one so ill just put the new one on tomorrow. I highly doubt its seized since I drove it 4 hours before and it was perfectly fine. But I will test everything you just said IDK why I didn't think of that. Thanks. if its not any of the things I have replaced or am going to what else could it be?
With all the part purchases I figured they will go out soon since I have everything pulled apart might as well replace them.

[walky_talky20]

Things other than what you've mentioned that could cause a no-crank:
- faulty central locking module or related wiring
- faulty park/neutral position relay
- faulty wiring between ignition switch and PNP relay
- faulty wiring between PNP relay and starter solenoid

[pimpinb5a4]

so here is the deal. I replaced the neutral/ park safety switch and tried starting the car and got the same thing. then I moved on to the ignition swich and replaced it tried starting the car and got nothing again! then I pulled the dash apart and checked the realys and they tested good, tried hot wiring the neutral safety switch anyways and still got nothing! so now I am pissed and it has to be a bad wire somewhere? I was going to test the starter like you said but there is no room to test it so ill rip it out again and test it! just angry as hell!

[OGBULLYLOCDAWG]

I don't know if the 1.8t has the same layout that my 2.8 C5 does, but I battled this issue a few times over the years, only to have it resolve itself before figuring what the problem was.

Only recently was I able to figure what the problem was, since it started doing it again right after the first snowfalls of the season started.

Of course it COULD be the starter in your case, but that wasn't the issue in mines, it was the ground strap that sat right above my alternator.

You can see where the ground strap bolts down after it comes off of the battery. Well, I guess that strap makes a connection thru the sheet-metal to a strap that's under the car, that's bolted to the motor(?). On my C5 2.8, the strap is bolted down right above alternator above/behind behind the electrical connector.

Maybe you're having the same issue? I had the exact symptoms.. turn the key and just one loud click. It was also responsible for my low voltage readings where the voltmeter would dip below 12 sometimes and the battery light would never turn on. On a good day I would get a max 13v charge.It was just enough voltage to start the car and keep it running and restart it after shutdown with extremely slow cranks.

---------
If you're laying under the car, it runs from the passenger(bolted down sideways into the metal) and goes across to the motor. Hopefully it's a similar setup, as I'm sure this post is confusing enough, lol.

If you're able to locate it, and it does look corroded -- clean it up a bit with a dremel + wire brush(or whatever you have handy), maybe even replace it if it turns out to be bad enough.

EDIT: Gotta remember that it may be a completely different layout to the 2.8, so just check for a ground strap coming out of sheet-metal to the motor or something like that.

[doperings]

Definitely check your engine grounds. I recently replaced a short block in a 01 1.8t, got everything back together and all I got was that single click, so i pulled the starter and did all that too, just to find out i had forgotten to ground the engine block back to the chassis. The starter in these cars dont have a dedicated ground to them and they ground to the block through the case so if the engine isnt grounded neither is your starter.

[walky_talky20]

Like I said, check it right at the starter. See what you're missing. Make sure you're getting the signal to the solenoid, solid battery voltage, and a quality ground to the starter case. For the last 2 it would be helpful to check them while someone attempts to crank the engine with the key. The ground can look good until you load it. Same with the 12v+.


On a 1.8T there is plenty of room to check this stuff when you have it on a lift. Be glad you don't have a V8 Lexus with the starter in the "V" of the engine - under the intake manifold. That's a bucket of fun, right there.