Generator Light Function

[Big Flapper]

What is the primary function of the generator light? I have a 2008 CTLS and the generator light has never (100+ hrs flying) come on, the bulb will light when tested.

Is there a way that I could get the generator light to come on when the engine is shut down and the generator breaker is still on?

[Anticept]

Generator light comes on when the alternator is engaged with the breaker, but not outputting.

[Madhatter]

With the breaker on and the engine not running the light should be on showing discharge.  If it's not on the bulb is bad.

[Big Flapper]

22 minutes ago, Madhatter said:

With the breaker on and the engine not running the light should be on showing discharge.  If it's not on the bulb is bad.

I have checked the bulb, It's OK. what should I look at next?

[Anticept]

If the bulb is bad, the hobbs wont run either.

There's always a tiny amount of current flowing, and on flight designs, the hobbs is on that circuit too.

If you say the bulb is lighting up, then that's all there is to it!

[Big Flapper]

2 minutes ago, Anticept said:

If the bulb is bad, the hobbs wont run either.

There's always a tiny amount of current flowing, and on flight designs, the hobbs is on that circuit too.

If you say the bulb is lighting up, then that's all there is to it!

My Hobbs continues to run but the bulb is dark.

 

[Anticept]

Then the bulb is likely good.

As said, turn the gen breaker on with master off. The gen light should come on.

[Big Flapper]

1 hour ago, Anticept said:

Then the bulb is likely good.

As said, turn the gen breaker on with master off. The gen light should come on.

I have done this, must be something in the wiring, I've looked at the wiring diagram but I can't see  anything to check.

I checked the bulb with a 12 volt battery and it is OK, maybe the voltage from the Gen circuit is lower that 12 volts??

[Anticept]

It's possible. Flight designs wiring sometimes doesn't follow the wiring diagram correctly.

It is on the wiring diagram, just difficult to identify. The bulb is hooked to the voltage regulator at both ends.

Check to see if the regulator has loose connections in the black terminal block. Again your hobbs is running though so it seems like its working.

I just tested mine 5 seconds ago and the bulb lit up as described.

[Madhatter]

I had to rewire a lot of my CT in accordance with accepted methods for certified aircraft. The CT electrical is a disaster, also lots of cheap spade connectors for points of resistance, the worst I have ever seen in any aircraft.

[Anticept]

And those automotive bullet connectors meant for 14 gauge wire being crimped on 20 gauge...

[GlennM]

This is totally anecdotal, but is your capacitor ok?  Mine was bad and the generator bulb did not come on as you describe. Once I replaced the capacitor, it started working again.  I have a CTSW, though.

[Big Flapper]

12 hours ago, GlennM said:

This is totally anecdotal, but is your capacitor ok?  Mine was bad and the generator bulb did not come on as you describe. Once I replaced the capacitor, it started working again.  I have a CTSW, though.

Checked all the wiring today, with the Gen breaker on the voltages on the light socket were 13.5 and 7.5 volts. No light. Voltages on the regulator were similar.

Checked the capacitor and while removing the fire shield one of the contacts broke off - looks like it was barely attached. So - Ordered a replacement, will let you all know if it may have been the problem.

Thanks for all the comments    Tom 

[Anticept]

You can do yourself a huge favor by retrofitting a larger capacitor instead with screw terminals. The little tiny 22kuf caps don't do a good job, the voltage regulators are terribly noisy and it's the capacitor that filters out a lot of the high frequency noise.

FDUSA does issue MRAs for PN ALS40A104KF025

[GlennM]

@Big Flapper I see you replaced your capacitor in the other thread.  Did it work to fix the generator light?

[Big Flapper]

1 hour ago, GlennM said:

@Big Flapper I see you replaced your capacitor in the other thread.  Did it work to fix the generator light?

The generator light is still not functioning. I believe that the problem is related to the voltage regulator that I installed some time ago. I installed a B&C regulator and the function of pin 5 is different from the standard regulator supplied by FD. Have to consult with my local electrician about a minor connection change. I will post an update later.