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KY97A backlighting

rv468

Active Member
I?m wiring a KY97A com in the RV4 that I am building. The manual is slightly confusing as far as wiring the backlighting. I have dimmer for my cockpit lights. I hoped to wire the com backlighting into this dimmer. I have a question for those that have done this. Do you run the power wire from the dimmer to the ?B? connecter on the com?

Thanks in advance,
Cameron Smith
RV4 #68
 
Cameron, the on-line source of manuals seems to have dried up.... :(

I just installed a KY-197 in a Great Lakes (similar, but different display) and found the manual a little confusing too.... Inputs and outputs did not seem to be clearly defined when they should be connected....

But I found this on a Cessna BB, and it might answer your question...

looking at the connector from the front of the rack, the contacts on the top are labeled
A B C D E F H J K L M N P R S
from left to right
and the lower contacts are 1 thru 15, again left to right.
the polarizing key is between J & K, 8 & 9.

R & 14 are Aircraft Power +13.75 VDC in
P & 13 are Switched Aircraft Power out
M & 11 are +13.75 VDC Power in
B is +14 VDC Lighting Hi
1 is Lighting Lo, and
A is Dim Select

P/13 and M/11 should be jumpered together.

"For tracking of a 14V lighting bus, leave Dim Select (Pin A) unconnected. When panel dimmer is turned all the way down backlighting goes to half brightness. If continous half brightness is desired Pin A can be connected to aircraft supply. If no connection is made to the aircraft dimmer bus and Dim Select, the backlighting will be at half brightness."

sounds like you've either got A connected to power, or A and B both disconnected. If you want it to follow the panel dimmer connect B to the dimmer circuit and leave A unconnected. Mine are wired for full brightness whenever the radio's turned on; B is connected to P/13/M/11.


Since it is a LCD display, you might want it on full brightness during the day if it's located in a "shady" spot on you panel...

Let us know how it turns out....

gil in Tucson
 
KY97A Backlighting

Gil,
Thanks a bunch for the info. I hope to wire it next weekend.

Cameron Smith
 
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