Over the past few days I finished up most of the engine sensor wiring. I still need to wire up the oil pressure sender and redo the EGT sensors. On the oil pressure sensor I decided to use my own Tefzel wire instead of using the cable provided by Rotax. I found the Delphi GT-150 connector on Ebay and it looks like it will be an exact fit. I had purchased some other 3 way Delphi GT150 connectors but it seems the pins are slightly in a different place so it doesn’t connect well to the sensor. Will provide photos when I wire it up.
For the EGT sensors I had originally purchased some Aviasport IM-927 K Type sensors which seem like they will work, but I was thinking that they may be a bit hard to service if I wire them directly into the GEA24. These sensors have 6 foot wire attached to the sensor which I was going to put pins on and connect directly to the GEA24, but if I ever need to remove them I’d have to depin the connector and pull the cable out through the firewall, etc. Also since the sensor screws right into the M8 thread on the exhaust you have to turn the whole thing including the wire which makes it even more difficult to change out. I contacted Aviasport and they said that you can extend the leads using K Type wire, but you can’t cut them. So to avoid having a loop of extra wire from the each sensor I order some Micro-1000 EGT sensors that seem like they have a much shorter lead. I can then run the K Type wire from the GEA24 out to the connector near the sensor. I’m hoping this will be a much cleaner install.
Another thing to note is that I changed back to using a single 22AWG shielded wire for each of the temperature sensors. I saw on some RV-12 build pages that they just use a single wire and not a 2 wire connection where one wire goes to the sensor and another to engine ground. The sensors themselves are grounded to the engine block (some temperature sensors have a separate ground wire which would require a 2-22AWG wire) so running an extra ground wire out from the GEA24 seems redundant and not necessary. The GEA24 ground and engine block will be tied together anyways so the only reason you’d run separate grounds would be to just be sure that you have a good ground at the same potential as the sensor ground. I suppose it would be no hurt in doing this, but you could potentially cause some ground loops. even if you wanted to ground those GEA24 pins to the block you could run one ground and jumper it to each of the pins. So it seems to me that you just don’t need to use those ground pins on the GEA24 when using these types of sensors. Now I could be completely wrong on this, but from the RV-12 builds I’ve seen it seems that you don’t need the extra wiring and if I am wrong I just need to run one wire from the GEA24 to the engine block.
I found some plastic covers that I cut one side off to use as a cover for the temperature sensor connections. It’s a little nicer than the bare metal of the FAST-ON connector.
Also put on a little conducive grease to help keep the connection corrosion free.
Finished connector. The other idea was to find a small boot that could slip over the top of the sensor and connector.
Bracket installed and hoses run to the fuel pressure and manifold pressure sensors. I still need to wire tie the hoses and sensor wires. I used 4mm silicone hoses and found some Hitachi clamps on Amazon that look like the Rotax hose clamps. Still waiting on the M6 hose barb for the fuel pressure sensor so that I can connect it to the airbox.
I used Delphi GT-150 3 way connectors for the fuel flow, fuel pressure and manifold pressure sensors. Rotax uses a 3 way Delphi connector on the oil pressure sensor, but it’s a little different pin arrangement (2 on top, one on bottom (like a triangle, not straight like these). There are a few other sensors (like the Kavlico) that use the Delphi connector. Also I found there seems to even be a variation on these 3 way triangle type connectors as well. Will detail more on that when I wire up the oil pressure sensor.