Help no power

[betterwith4]

no power to fuse 12 got no ignition any ideas guys? Might be able to fix my frigging car after 2 week of checked random things earth etc s2 coupe 94 aby

[Error404]

Fuse 12 is nothing to do with the engine, its for the instrument cluster, interior lights etc.
The engine related fuses are on the bottom row, 23 - 32 IIRC. did you mean one of those?

[betterwith4]

But i have no ignition. .. got power all round the car ... replaced ignition relay theres power going through that but only thing that doesnt work is all my clocks amd nothing happens when i turn ignition to on any clues?

[Error404]

Do you have an immobiliser on the car or have you or a previous owner been rooting about under the driver side of the dash? Disturbing connectors on the underside of the fuse board could cause all manner of problems. Have you tested the ignition switch?

These are the engine fuses.

S24 = 10A [ISV, WGFV, Evap solenoid]
S25 = 10A [Lamda heater]
S27 = 20A [ECU]
S28 = 15A [MAF, Injectors]
S32 = 20A [POS & Coils]

S24, S25 & S28 are switched by the fuel pump relay.
The fuel pump relay will only activate if the ECU sees the hall sensor, crank position & RPM sensors. If the fuel pump relay activates on cranking then the ECU is happy with these. It triggers the fuel pump relay on pin 47/1 from pin 3 of the ECU connector.
So assuming you have no faulty hardware, if fuel pump relay is active, fuse 32 is OK and you have +12v to the coil power supplies (2 x white 3 pin plug on firewall bracket), the engine will start.

[betterwith4]

Your going to have to explain the s numbers im only like halfway with electonics im afraid so im going to need to dumb version "/

[betterwith4]

Ignition switch is new i replaced it to get rid of that possibility

[Error404]

Sorry an S number indicates a fuse on the OEM wiring schematics. So for example S32 would be fuse 32, on the ABY/RS2 this is for the ignition coil circuit
So check fuses 24, 25, 27, 28 & 32 are all OK.

So just to clarify, Exactly what is happening.

You have no ignition lights on the dash?
Engine does not crank when ignition key is turned?

So sounds like you have no connection between ignition switch & fuse board - check this. Here is a diagram of the underside of the fuse board:



The ignition switch should be connected as follows:
to pin F50Z with a chunky red/black wire [large brown 8 pin connector]
to pin J15 with a chunky black wire. [large yellow 6 pin connector]
to pin G75 with a small black & yellow wire [large red 8 pin connector]

If any/all of these are disconnected or damaged you would lose most if not all of the power to the dash and other switchgear and also lose your connection from the ignition switch to the starter.

Here is a pic of the rats nest you will be dealing with:



HTH
Alex

[betterwith4]

Thanks mate ill take a looksee around

[UrS4boy]

Fuse 12 is nothing to do with the engine, its for the instrument cluster, interior lights etc. The engine related fuses are on the bottom row, 23 - 32 IIRC. did you mean one of those?

I agree about Fuse S12 for an S2 - with one exception. It is also the fused power for the F76 Multifunction Temperature Switch (MFTS) that we know the ABY ECU is influenced by (to some degree). Black/blue wire.

F76 MFTS info: http://forums.quattroworld.com/s4s6/msgs/22584.phtml

[Error404]

ok yes, it also has the diagnostic protection too, but really I meant the engine will 100% run without S12 (yes it might not boost correctly)

[betterwith4]

Right ... update ... pulled fuse box out and look into the blocks at the back they seem free from rust and damage no fuses blown my headlights come on when i turn the key to were the ignition SHOULD come on ... no reverse lights ... theres power going through my ignition switch but power not getting through fuse 12 for clocks etc any ideas yet guys? Power still good in the battery for now 12 volts still power still all round the car windows work wipers and washers work heater works radio works central locking works interior lights works head side and fog lights work ... any clues? Dont for get to guve me simple terms hahaha

[quattro-nick]

according to the wirediagram there goes a black wire (2.5mm thick) from ignition switch to the fusebox that gives power inside the fusebox after you turn the key to ignition were also fuse 12 getting power from
check if you have 12v on this wire on the back of ignition switch on steering column.
if not,disassemble the ignition switch and try to start with a screwdriver in the ignition switch.
if it's start you have a mechanical failure of your key cylinder
if you have 12v power on this black wire on the ignition switch you can check if you have 12v power on the fusebox on the same wire.i think it's on place j15 on the fusebox
if you getting there 12v then your fusebox is damaged.
i hope this helps you

[betterwith4]

according to the wirediagram there goes a black wire (2.5mm thick) from ignition switch to the fusebox that gives power inside the fusebox after you turn the key to ignition were also fuse 12 getting power from
check if you have 12v on this wire on the back of ignition switch on steering column.
if not,disassemble the ignition switch and try to start with a screwdriver in the ignition switch.
if it's start you have a mechanical failure of your key cylinder
if you have 12v power on this black wire on the ignition switch you can check if you have 12v power on the fusebox on the same wire.i think it's on place j15 on the fusebox
if you getting there 12v then your fusebox is damaged.
i hope this helps you

That last 2 lines doesnt make sense lol could you reword it 😁😨😁😂
Thanks
Jamie

[newsh]

Pulling the fusebox out sounds like a very bad idea. Won't a lot of wires get pulled off the underneath?

Incidentally, in the diagram above of the fuse box there is no J15.

Jamie, what Nick is saying is that it's possible for the tang at the back of the ignition key lock to be broken, so when you turn the key it doesn't fully turn on the ignition (even with a new ignition switch)

You need to check that the black wire on the back of the ignition switch is going +12v when you turn on the ignition and that terminal J15 on the fuse box is going +12v too, if it isn't getting from the switch to the fuse box then there may be a break between the switch and the fuse box and I would suspect an immobiliser to be fitted and not working properly.

[steverrquattro]

I normally do all my own work, but why not just get an Auto Electrician to look at it?

I recently had a problem with my car and spent a couple of days checking everything and thought that it was the alarm that had gone faulty. This guy came out, did a few checks, snipped a few wires, made a few circuits then ripped the CAT1 Thatcham approved alarm out.

Within a couple of minutes the car was started and it's the best £30 I've ever spent.