# Knock box + ICM wiring diagram?



## ncbrock (Sep 28, 2010)

I decided to run a knockbox and a 7 pin icm setup with my carbs and am having trouble finding a good diagram to follow. Ive been searching for a while and cant turn up what I need. All I can find are people saying "Yeh, I run a knockbox setup"


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## ps2375 (Aug 13, 2003)

The diagram from a Bently for any 16V with cis-E like what a 16V Scirocco runs should work. Since the spark is independent of the fuel, all it needs is power, a vacuum signal and the signal from the dizzy to work.


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## ncbrock (Sep 28, 2010)

could anyone explain the knockbox pin numbers to me? There are 8 pins on the top and 7 pins on the bottom, and this diagram lists them 1-15 like they are in a straight line


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## ps2375 (Aug 13, 2003)

Do you have the Bently Manual for the car this came from? I think it should show how the pins are ordered out in the connector. Or you can look on the connector for the pin numbers. And the wire colors are on the diagram, you should be able to figure it out with those alone.


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## ncbrock (Sep 28, 2010)

ps2375 said:


> Do you have the Bently Manual for the car this came from? I think it should show how the pins are ordered out in the connector. Or you can look on the connector for the pin numbers. And the wire colors are on the diagram, you should be able to figure it out with those alone.


I guess it would help if I had the connector I got the wiring diagram from driversfound.com not a bently, though it would be really helpful if I got one.


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## L33t A2 (Aug 5, 2003)

*FV-QR*

generally in the computing world a 15 pin connector would have this sort of standard pinout...









Note that it says male connector, that's the half with the pins sticking out if you weren't sure, a female connector has holes instead of pins 

NOW as far as the knock box is concerned, i really don't know for sure


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## srgtlord (Jun 4, 2010)

Or you could ditch the knockbox and go for the simple ignition setup with 6 wires , or 2 wires with points......


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## ncbrock (Sep 28, 2010)

srgtlord said:


> Or you could ditch the knockbox and go for the simple ignition setup with 6 wires , or 2 wires with points......


this doesnt seem too complicated to me, plus the benefits of it are great compared to others. Running a knockbox is about as good as its going to get next to programmable, which will be my next step once cash allows. The knockbox has a 3d timing curve which is what im after.


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## -RalleyTuned- (Nov 17, 2008)

Are you starting form scratch with blank connectors? 

the bentley diagrams are much better than the one you found...


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## ncbrock (Sep 28, 2010)

-RalleyTuned- said:


> Are you starting form scratch with blank connectors?
> 
> the bentley diagrams are much better than the one you found...


i dont have any connectors at the moment. I think im just going to rip the whole setup out of my cis-e car, but it was a last resort.


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## -RalleyTuned- (Nov 17, 2008)

Just take the looming apart and remove everything you don't need, its super easy, just kinda messy

you wont need a diagram so long as its a complete harness


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## YJSAABMAN (Jun 28, 2006)

Popped up in the bike carbs thread:










I have another one, too, but I can't find it right now.


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## ncbrock (Sep 28, 2010)

If anyone could help me out with wiring it would be greatly appreciated, I only have 3 wires left that are unknown. Ive looked at 3 diagrams and cant figure it out, I know brown is ground but why two? One wire is green\yellow the other two are straight up brown








By ncbrock at 2011-12-31

Also according to all 3 I should have two brown\yellow's (which I dont) and on the 2nd diagram it says for the brown\yellow to go to the starter, and on the 3rd diagram it says for the brown\yellow to go to the fuel pump (which you cant see)









By ncbrock at 2011-12-31









By ncbrock at 2011-12-31









By ncbrock at 2011-12-27


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## ncbrock (Sep 28, 2010)

Bump kinda need help got to get this thing running asap


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## ps2375 (Aug 13, 2003)

what is at the other end of them? The diagrams don't show any grn/y wires,,, What car is the stuff you have from, maybe looking at a diagram for that car would help.


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## ncbrock (Sep 28, 2010)

its from an 85. Ill try and chase the wire tomorrow


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## ps2375 (Aug 13, 2003)

ncbrock said:


> I guess it would help if I had the connector I got the wiring diagram from driversfound.com not a bently, though it would be really helpful if I got one.



This is what you need, a Bently for the yr make and model that what ever you have came from. When we swapped a 16V into the 80' and ran it on the 80's CIS and used the 87's knock control ign, we had both manuals, it basically made the whole operation plug and play. And it made stripping the wire harness for the ign very easy and we never had any problems with the spark from day one. If you don't have the correct tools for the job, you just make it that much harder. And the Bently Manual is a tool that makes all this stuff that much easier. GL


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## ncbrock (Sep 28, 2010)

The green\yellow goes to this connector by the firewall along with what looks like the knock sensor wires (black\red and violet\white) 








By ncbrock at 2012-01-02


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## ps2375 (Aug 13, 2003)

Dunno, when we removed the harness for the knock box/spark control on the 16V Scirocco, everything was on the motor side of firewall, nothing went inside the pass compartment. Another reason to have the correct tools.


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## YJSAABMAN (Jun 28, 2006)

That's the other one I'd been using, thanks. 

What terminal on which part of the ignition does your mystery green/yellow wire extend from?


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## ncbrock (Sep 28, 2010)

well if i knew what terminal everything came from nothing would be a problem. how are you supposed to tell what terminal a wire comes from when the connector prevents you from seeing anything?


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## YJSAABMAN (Jun 28, 2006)

ncbrock said:


> well if i knew what terminal everything came from nothing would be a problem. how are you supposed to tell what terminal a wire comes from when the connector prevents you from seeing anything?


This makes no sense. The connector is what tells you which terminal. Let's try this a different way...

Does your mystery wire come form the knock box or the ICM?

With the (insert source of mystery wire here) sitting flat on the mounting surface on a table with the connector facing you start at the left pin (#1) and count to the right until you get to your mystery wire.


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## ncbrock (Sep 28, 2010)

Im not sure about your knockbox connector, but my knoxbox connector is just a bundle of wires that runs into the connector. There would be no telling what wire came from what terminal.








By ncbrock at 2012-01-10


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## YJSAABMAN (Jun 28, 2006)

Either the plug or the knock box will have at least 4 numbers on the connector, one at the start and end of each row. I forget exactly how the knock box is laid out.


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## doctor12valve (Jul 20, 2005)

ncbrock said:


> Im not sure about your knockbox connector, but my knoxbox connector is just a bundle of wires that runs into the connector. There would be no telling what wire came from what terminal.
> 
> 
> 
> ...












Call us tomorrow, I'll order you one :thumbup:


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## ncbrock (Sep 28, 2010)

ive got that one and a golf\jetta one. Unless you spend a lot of time studying the current flow diagrams, they dont make a whole lot of sense. I can make out some things but id need someone that knows what they are looking at beside me to tell me 100%


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## revolution_Jd3 (Jan 13, 2007)

old thread... hope you got it whooped. if not figured i throw this in here for further peoples searches.

http://www.driversfound.com/scirocco/techtips/engine/knocksensor/


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## YJSAABMAN (Jun 28, 2006)

revolution_Jd3 said:


> old thread... hope you got it whooped. if not figured i throw this in here for further peoples searches.
> 
> http://www.driversfound.com/scirocco/techtips/engine/knocksensor/


Great addition to this thread! :thumbup:


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## MacGruber (Aug 20, 2010)

WATCH OUT for the screwy wiring advice here.
"Drivers Found" is just another Vortexer who can make a mistake like anyone.

That mystery wire from the KNOCK BOX to the STARTER 50 (Solenoid 12V during cranking) _ncbrock_ has an issue with, supposedly from T10 on the Knock Box. Obviously there is no reason at all to send 12V into T10 of the Knock Box during starting. 

T10 in fact is a R/Y wire added to ground the 4-pin CIS-E fuel pump relay and turn it on. So add the new wire or use the old relay.

Fuse 17 was reserved for the Knock Box power supply requiring another new wire.


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## betterfood (Oct 4, 2018)

I'm working on a carb + knock box + ICM setup right now. I took my knock box apart to sort out this T10 thing.

My box is part number 811 907 397 E. The one with yellow lettering. Cannot guarantee the internals are the same for the other one(s).

T10 is connected directly to the collector of an NPN transistor, a BC337 to be exact. The emitter is connected directly to ground (T3).

This make sense, as MacGruber stated, it drives the low side of the fuel pump relay. I can only assume this is done so the fuel pump does not run all the time when the ignition is on and the engine is not turning. The knock box does this rather than the fuel computer as it's the one with the RPM input.

Time for some assumptions and a hypothesis.

Assuming I am correct in that the fuel pump will be shut off in the absence of RPM. I also don't think these cars prime the fuel system, otherwise there would be no point to the fuel accumulator, the knock box could issue a prime pulse, I'm not sure. This means when you turn the ignition on you will see 12V on T10 through the fuel pump relay coil while the pump is off. While cranking you will still see 12V while the knock box gets synced to the RPM signal, and then probably a bit of a delay in your meter. Once RPM is detected and the transistor is turned on current will flow though the relay and you will then see 0V on T10 just about at the same time you stop cranking. This makes it look like T10 is receiving power during cranking and I bet the origin of the powered T10 myth.

What does this mean for people who connect T10 to 12V? You killed the transistor and it doesn't do anything anymore. Which is fine because if you weren't using T10 as originally wired you don't need it anyways.

Unless of course there are different knock boxes that do different things with T10. In which case this only applies to the E variant. Everyone send me your knock boxes so I can take them apart!


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## MacGruber (Aug 20, 2010)

Take a look at the Bentley schematic for *Engine Controls - 16-valve Scirocco* and notice the +12v wire running FROM the starter (called 15a) - actually 2 wires, 
one to the Cold Start Valve.
one to the ECU T24 - a cranking signal.

No starter wire leads to the knock box.

How does the fuel pump prime? My CIS car primes via the large fuel pump relay receiving ignition switch +12v. If the pressure is already high enough the fuel pump doesn't do anything.


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## [email protected] (Dec 8, 2007)

MacGruber said:


> How does the fuel pump prime?


IIRC the knock box primes the pump at power on for a second, then it shuts the pump off until until the engine starts turning (hall input).




MacGruber said:


> If the pressure is already high enough the fuel pump doesn't do anything.


strange, there is no fuel pressure switch or sensor so I"d say the fuel pump priming is not pressure related..


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## betterfood (Oct 4, 2018)

MacGruber said:


> Take a look at the Bentley schematic for *Engine Controls - 16-valve Scirocco* and notice the +12v wire running FROM the starter (called 15a) - actually 2 wires,
> one to the Cold Start Valve.
> one to the ECU T24 - a cranking signal.


The scheamtic I am going of shows a "cranking" wire to T24 on the fuel computer as well. Not sure why the CIS computer cares though. On an electronic injection system it would go into a different cranking map. On CIS the cold start colenoid is driven directly from off the starter. Must do some other stuff durring cranking. Regardless I think we both agree T10 does not go the the starter.



[email protected] said:


> IIRC the knock box primes the pump at power on for a second, then it shuts the pump off until until the engine starts turning (hall input).
> strange, there is no fuel pressure switch or sensor so I"d say the fuel pump priming is not pressure related..


That's exactly what I was going to ask/say. Even if there was a pressure switch, the knock box controls the fuel pump and it definately does not have a pressure switch input.


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## VenousSAGE (Sep 23, 2013)

Bump, having similar issues with my swap, im integrating a knock box from an 87 16v scirocco into an 85 8v harness.


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