LSJ dash wiring questions

[Speedytec]

Hi all,

I do not own an Atom, but as I am planning to swap an LSJ engine into my Opel Speedster (= Lotus Exige derivate), we will be "cousins" in a way. 

I am now busy with planning the wiring. I have the GM LSJ P12 diagrams but run into a some problems with the dash wiring as the Cobalt & Redline instruments are driven through the OBDII.... But as the Atom uses a Spa dash, you guys maybe have an answer for me on these questions:

How is the Atom LSJ RPM signal pick-up done? 0-5v signal from the PCM? Which pin? Or direct pulse pick-up from the ignition??

How is the engine water temperature signalling done? From PCM (pin?) or through a separate sensor?

Thxs.

[bolus]

I believe Terry Kennedy is one of the few (if only?) one of us that has an Atom wiring diagram so you can try sending him a PM. 

[Speedytec]

Spent some time again with the search button:

If I'm reading correct ( http://forum.atomclub.com/index.php/topic,4207.0.html ) in the Honda the Spa dash uses a separate ECT sensor to log engine temp. That will probably work the same in the LSJ version. Will see if I can intercept the ECM PCM signal, otherwise I will follow the same route for my conversion. 

Leaves the RPM signal. Read somewhere that the Spa dash can be programmed for different # cilinders, so probably there is a direct wire somewhere from the ignition. Anybody know where exactly??

Thxs

[bolus]

The LSJ Atom uses a 5 volt(I think) for coolant temp since there is a voltage grounding problem with the Atom that makes the temp off quite a bit if you turn the headlights on.  There is a coolant temp by OBD too of course.

[Terry Kennedy]

[quote="bolus"]
I believe Terry Kennedy is one of the few (if only?) one of us that has an Atom wiring diagram so you can try sending him a PM. 
[/quote]

I don't have anything close to a complete diagram. I do have a couple pieces which describe the various connectors. I have a Microdash, not the regular dash, so things are a bit different from the rest of you.

[Speedytec]

Well, your microdash also needs an rpm &temp feed from somewhere, so maybe you can shine a light on this.
Would help me a lot if I know where the rpm pick-up is on the LSj.

Thxs

[bolus]

does it turn on with the running lights?