electrical and ignition Anyone Using The Megasquirt Relay Board?

[tdk930]

Anyone using the Megasquirt for EFI and using the relay board?  Looking for feedback on how to run the RS232 from the relay board to the CPU.  Did you cut your own hole through the firewall or is there somewhere to run this through an existing opening?

 

Any other help or feedback would be great. 

 

Thanks for the help.

 

Todd

 

[stuff]

I put my ECU and relay board under the back seat to reduce clutter elsewhere in the car. I used DIYAutoTune.com's longest premade MS3X wiring loom for the MS3X connections (spark, injector grounds), and their longest loose wiring bundle to run from the relay board to everything else (TPS, CLT, MAT, injector 12v, etc.).

All wiring (except fuel pump and unswitched 12v, which go to the boot) exits from under the back seat through a factory hole in the rear seat front support, including the USB cable for connecting to the Megasquirt ECU which emerges from a hole in my ratty carpet behind the driver's seat. I also purchased a RS232 to Bluetooth dongle that will eventually replace the USB cable. In an ideal would all these sensitive ms cables would not sit beside the main power feed from the battery, but no issues so far.

Cheers,

Colin

[Chamonix72]

My ECU and relay board are in the glove box. So, there is one hole that had to be drilled through the firewall for the ECU wiring. The harness to connect the relay board was shortened (not by me, thankfully) to fit in the glove box. 

[scanner]

i followed this video from DIY Autotune 

My MS is sitting at the centre console and the relay board down the side of the engine bay http://www.bmw2002faq.com/topic/134019-73-fjord-with-megasquirt/page-2 3/4 of the way down the page. Sorry just thought mine is RHD so positioning may not work so well, its there for what its worth!

[stuff]

+1 for installing in the centre console.

I probably would have used the centre console too if I had one fitted.

Scanner,

I was born on the South Island (moved from NZ to UK to US)... good to see a fellow kiwi on the board! Where are you located?

Cheers,

Colin

[tdk930]

Thanks. I was hoping to route it through an existing hole and I don't see any other than the one that routes through the foot-well to the rear of the fender but may cable is lot that long.  I think i will just drill the hole and mount it in the glove-box. 

[mike472]

My relay board is mounted on the passenger's side firewall on its own stainless plate with two rubber mounts.  The fat ECU cable is running through the unused A/C holes.  I used one hole for the cable to the ECU and the other for a E30 battery cable setup from under the rear seat. I had to enlarge one of the A/C holes with a socket punch to fit the big ECU connector through it.  You have to partially disassemble the connector and twist it sideways to get it through the hole.  I ran it to the ECU which I velcroed to the underside of the metal dash over the glove compartment.  Don't drill any holes there or you will create leaks.  Colin idea of mounting everything under the rear seat is great.  Probably the way to go to avoid clutter in your engine compartment.   The sensor wiring will fit through the stock A/C holes with no enlarging if you go Colin's route.  The wiring may be a little on the long side, but as long as your getting a signal from your ignition trigger on that now somewhat longer shielded cable you should be OK.  If Colin already got it working well that way I'd go that route.

[AustrianVespaGuy]

I built my own relay board instead of using the MS relay kit so that I could also rewire how the headlight relay works at the same time (which is the single DUMBEST piece of factory wiring on the car, btw).  But anyway, I actually mounted my MS directly to the heater box behind the center console so as to keep my glovebox freed up, and then drilled a hole up high in the passenger foot well to pull the main harness through.  If you go this route, please DO be mindful of leaving enough clearance around your hard brake lines on the firewall, just to be one the safe side.

 

-Carl