Sunday, December 13, 2009

Making sense of Spaghetti

After receiving the engine, gearbox, loom etc a couple of weeks ago I decided that it was about time that I got stuck in to doing some work on the project. Having received my ODBLink on friday and also some wiring schematics for an RX8 earlier in the week I decided that the first place to start was the big mess of wiring that I have which looked like this...

After a few hours of looking over the wiring schematics and sifting through the big mess of wires I was able to untangle them somewhat and it started looking a little more reasonable. I identified about 40% of the plugs in the loom, still a bit to go though... Without the schematics though things would be near impossible, I guess thats one the issues of not taking the loom out of the car yourself.

This is what 20 odd pages of laminated (they should last the build laminated) schematics looks like. And this isn't all of them!

I also wanted to see how the new OBD tool I bought wworks but because I dont have a key for my loom I can't really talk to the RX8 ECU just yet. So I took the opportunity to borrow my fiance's freinds car while they were out looking for dresses and see what sort of data I could get from the CAN bus in her Mazda 2. I was a bit worried the tool I bought might not be able to give me the underlying CAN data from the car but after a bit of searching I found a great pdf for the ELM327 chipset used in the ODBLink. After a few 'AT' commands sent to the device I was able to receive the raw CAN data which I am going to write some basic software to interpreret. For the time being I am just using hyperterminal in windows.

Once I've written some .Net code to interperet the CAN frames I will post the source up here...

No comments:

Post a Comment