12-03-2014, 12:22 PM
Join Date: Jun 2009
Total Cats: 0
NB2 Auto to Manual Swap
I am currently doing a swap for a 2005 NB.
I have been following this guide http://forum.miata.net/vb/showthread.php?t=462578
and I am very confused with the speedo wiring instructions.
Now this one is a little tricky. You need the speedo sensor that comes with the manual transmission. Make sure you get a tranny that has all the sensors plugged into it. (or get all these to go with it)
I hacked the connector off of mine and tied it into the Yellow and Orange wires from where the auto speedo plugged into. (one of the dangling connectors has yellow and orange wires, pretty easy to locate) I did not pay attention to polarity and I'm not sure it matters. Mine worked on the first try. If yours doesn't, you could try swapping the two wires - but my best guess is it doesn't matter.
Pull your gauge cluster out of the dash. (yes, your gauge cluster) This requires removing the steering column cowl (three phillips screws from underneath - then separate upper and lower halves) - Then pull the gauge hood off the dash. It pulls straight back toward you and pops off. Now there are four phillips screws surrounding the cluster. Remove these, and you're there.
Turn the gauge cluster to point the gauges up. You'll find three connectors on the back. The larger white one on the left needs to be unplugged.
You will find an empty slot for a pin between the White with red stripe and the black with some sort of stripe (purplish or reddish) It's the fourth position on the connector. You need to insert a pin here if you can get one or do what I did - use a solid core wire and fold it back a little so it will work as a pin and make contact with the cluster flex circuit. Just be sure it sticks out a little with some pressure applied to it and you should be good.
Run that wire down behind the dash with the harness. Make sure it's long enough to reach near the fuse box (leave some extra to play with)
You should have the auto ECU removed and the manual ECU in its place. The auto tranny controller is the small unit next to it. That also needs to come out. You will be connecting the wire you just added into that plug where you see the Yellow wire. I used the solid core wire and wrapped around the connector once, then pressed it in. Mine is held in place with a ziptie.
Lastly, jumper together the Orange wire and Black with White Stripe wire. They sit right next to the Yellow wire from the previous step. I also held this wire in with a ziptie.
Now everything should work. My speedo operates correctly, but I haven't checked calibration. I don't know which speedo sensor I have. My check engine light hasn't come back since I reset the ECU, either.
Am I suppose to connect the Yellow wire at the ECU end or near the clutch pedal where the old Auto Transmission ECU was?
When it says "jumper together
" does it mean disconnect it from the plug and just connect them together, or leave the wires connected to the ECU plug and get an extra wire to bridge these two Orange wire and Black with White Stripe wires together? And are these wires at the ECU side or near the clutch pedal where the old Auto Transmission ECU was?