Wiring G3X engine sensors

crabandy · #1 07-30-2013, 11:03 AM

Any gotchas on wiring the engne sensors for a G3X system?
I put blade connectors for EGT/CHT
The shields only get grounded at the connector side?
Inline fuse for 1 amp ammeter connection at the shunt, or a fuse able link.

MarkW · #2 07-30-2013, 01:34 PM

Crabandy,
I am suprised you have not gotten any responses.
I just finished all my firewall forward G3X installation earlier this month and there are no gotchas. Yes, on the few wires that get shielded they are only drained on the shell end. I built fuseable links for the shunt end. I am suprised you are using blade connectors as the CHT/EGT come with #4 ring terminals. I just ordered 20 #4 ring crimp-ons from Steins and used those. Also used his Thermocouple wiring.
I counted on the GDU to get the proper volts reading without running a serperate wire for voltage but found it read low since I connected the GDU to the ess. bus. Now I have run two voltage wires so that I can read main bus and ess. bus.

crabandy · #3 07-31-2013, 11:53 AM

Thanks Mark, I mostly went with the blades because I didn't have any #4 rings and didn't want to wait to get some. The drawings Stein sent make a lot more sense now that I've started the wiring.
On your fusable links i believe the wire to the shunt is 22 awg, did the link consist of 26 awg? I was worried about the little wires breaking plus the smallest wire I have on hand is 24 awg.
Thanks,
Andy

MarkW · #4 07-31-2013, 12:14 PM

A fuseable link is most about having a controlled place to fail. It needs to be right next to the power source (shunt). 24ga. would work as it is weaker that the 22ga you are connecting to. Just protect it as it will be warmer that the rest and if it fails it will get very hot. A special fiberglass covering is specified but I think a few layers of heat shrink would work. Have fun. I am working on the radio stack harness now. I finished up the G3X stuff a few weeks ago.

9GT · #5 07-31-2013, 02:12 PM

I used blade fuses for the shunt hook-up and clipped off the ring connectors on the probe wires. I replaced them with male/female d-sub pins/sockets then heat shrink tubing over the individual connections with a larger one over both connections and the K- wire to hold it all together.

crabandy · #6 07-31-2013, 04:21 PM

Fuses are supposed to protect the wiring, but he install manual says:

"The shunt should be installed in-line with the current being sensed. As noted below, the appropriate wire should be cut and attached to each of the large 1⁄4” lugs. A one amp fuse or other form of circuit protection must be installed between the shunt and the applicable GEA 24/GSU 73 inputs to prevent inadvertent damage to the GEA 24/GSU 73"

In this instance is the 1 amp fuse protecting the device?
Perhaps the 24 awg fuseable link on the 22 awg wire would allow more than 1 amp to go to the device?
Sorry probably a little paranoid but I'm getting close to hooking up the batt for the first time and I'm hoping for no smoke.