EX3 Ignition Check/G3X

[Mark Keneston]

Hi Builders. Yankee 1 is on the home stretch and with a successful smoke check, I found my ignition not functioning like I hoped. Jeepgord and I figured it out. While powered up I did the key check to be sure that the LED lights worked as they should when the key was on OFF, L,R & Both. I was getting results not consistent with what you should when doing a key check.

I did not have the IBBS battery in and without it, there is no power to the R side UNLESS you flip the emergency switch on. I battled with it and it was pure luck trying the emergency switch. We checked all the wiring and did find one out of place but that did not fix the issue I was having. I even consulted the factory and we did not get deep enough in it before Gord and I nailed it.

Be sure to try all your avionics before installing the boot cowl as many have shared here and if by chance you have inconsistent ignition checks, look at your emergency switch. I can share more detail if ya need. Thanks Yankee 1

[stautz]

I am having a similar problem with my ignition testing but I have the IBBS battery installed.

If I have the emergency switch on, then everything works as it is supposed to.

When I turn off the emergency switch and do the tests I get the following:
Switch Left – Shows right ignition off (right LED on)
Switch Right – Shows left and right off (both LED’s on)
Switch Both – Shows right off (red LED on)

I am checking through the wiring now but was wondering if I need to charge the IBBS battery somehow.

[Andy]

I did not have the IBBS battery in and without it, there is no power to the R side UNLESS you flip the emergency switch on.

Are you suggesting that is normal or are you saying this was the problem that you found?

IBBS should have no influence at all on availability of main battery power to either L or R ignition system. I can see nothing in my review of the schematics that shows the ignition warning LED would depend on IBBS either.

The CC ignition schematic shows the two ignition warning LED are connected in parallel (with reversed polarity) between pins 14 of the two ignition modules. This seems to be exactly as shown in the Dual Ignition Indicator lights schematic shown on the last page of the ignition system manual except that the CC schematics add a suppression capacitor and the wires for the G3X ignition alert messages.

Even if you meant "emergency ignition battery" rather than "IBBS battery" it should still make no difference. Both ignition systems should be powered by main battery if the emergency ignition switch is in the "normal" position and both warning LED should be functional.

[stautz]

My RT IGN EMERGENCY switch LED is broken and I am trying to get it fixed to verify everything is working. It looks like the switch was backward (upsidedown) but won't know until I get the LED fixed.

[Andy]

My RT IGN EMERGENCY switch LED is broken and I am trying to get it fixed to verify everything is working. It looks like the switch was backward (upsidedown) but won't know until I get the LED fixed.

I don't know if wire color codes are the same for the kits as for the FX-3 but this picture shows my emergency ignition switch which is the right way up and works as expected. This is a modular panel so switch position may not be the same as your. My switch group is emergency ignition and fuel pump, with provisions for pitot heat (not yet wired).

Emerg Ign and Fuel pump switch group.PNG

If the photo doesn't help it shouldn't be too hard to check for continuity between center pole contacts and upper and lower ""way" contacts to see which way should be up. The switch is 2 pole 2 way.

[stautz]

UPDATE:

I found the problem. It turns out the 10Amp fuse for the Ignition backup battery was blown. Therefore the backup battery was missing as described in the first post.

Now system works fine with or without the emergency ignition switch on.

For clarity, I wish the IBBS was named BBS so that the I is not misinterpreted as ignition.

[Andy]

UPDATE:

I found the problem. It turns out the 10Amp fuse for the Ignition backup battery was blown. Therefore the backup battery was missing as described in the first post.

I don't think you have found your problem. Neither the presence of the emergency ignition battery, nor the condition of the ignition battery fuse, should have any influence on how the ignition system operates when the emergency ignition switch is in the NORMAL position.

When I was learning how the emergency ignition system worked I found it helpful to trace the circuit through the emergency switch for both switch positions. It may help to make two copies and highlight the active circuit for NORMAL on one copy and for EMERGENCY on the other.

[kevino]

Could Andy show us the schematic he has for the emergency ignition system. Thanks

[Andy]

Could Andy show us the schematic he has for the emergency ignition system. Thanks

I don't know if CubCrafters permits their schematics to be published in a public forum and I have signed a non disclosure agreement. The ignition schematic is in the CCX/CCK maintenance manual and is included in the "main wiring schematic".

[stautz]

Just went through the long ignition test from the dropbox and everything works as expected. Thanks for all the help.