Sixline

Leave the blue wire disconnected. It can be used as an alternative to the grey reset button(Say you had 5 counts, if you grounded the blue wire it would reset to 0).

Red goes to switched power for the backlight, black goes to ground, and white goes to the KLR yes/no knocking output(pin 15 on the KLR plug).

Make sure the DIP switches are set for Current Sourcing Output as shown on page 6 in the manual.
http://www.redlion.net/Products/Grou...Docs/01024.pdf

bumflick

Doh - that explains a lot... Thank you.

And I will double check the DIP switches again - I read the documentation a couple times and think I had them set up right, but it can't hurt to check.

Gonna do this tonight (or at some point this week, or this month)
https://rennlist.com/forums/4032788-post62.html

victor25

Does anyone know what pin on the diagnostic plug is for the knock count on an S2 ??

mikey_audiogeek

Check Eric's 944 S2 supercharged thread - he has attached a document that lists the pinouts.

Dougs951S

Is having a digital readout of knock counts really all that important if you have knock control via a standalone and datalogging? Ive been thinking about installing a knock counter, but my ecu already pulls timing and logs knock events so is it worth while beyond say, dyno tuning for best timing?

Eric_Oz_S2

Knock counting is very useful for tuning. You do not want to rely on the DME pulling timing as a frontline defence. Conditions change from the dyno an it can be useful in flagging problems.

bumflick

I would rather know. There is a difference between 2 knocks per WOT run and 20, or 200. And I though I don't have knock control - other than the KLR - i'd prefer to have the visibility into what the engine management is seeing, so I can understand what it is doing.

victor25

found it at the bottom of post #1 of your supercharger thread, thanks Eric

Dougs951S

Just seems like a lot of expense that im having trouble justifying when I can already get the same visibility in real time on my laptop. I wish there was a cheap solution.

victor25

Well for about 50 cents you could just hook up a bright red LED with a resistor.

Dougs951S

Really? I actually thought about doing just that, but i wasnt sure if the knock sensor would output enough voltage to light it. So just ground the led, and attach the hot lead to the knock sensor output with idk, like a 1kohm resistor in line?

victor25

yep.... you should get whats called tip in flashes here and there when shifting or first getting on the throttle. Thats ok, Its the 1/2 or WOT ones your worried about

bumflick

If you have a laptop in the car that gives you the information, then more power to you. I dont keep a laptop in the car, and for ~$60 in parts and about an hour or two of effort, I see this as a less expensive (and less space consuming) option to provide the desired info.

Besides, if I did not like doing this kind of thing, I would not have bought a 25+ year old car.