Garmin 335 power connections

[von_flyer]

I have pin 21 and 42 connected to power (+14vdc) and pins 20 and 41 connected to ground. No joy on power up. Do I need 38 (power control)
Connected to ground? Am I missing something else?

Thanks in advance!
John

[Raymo]

Originally Posted by von_flyer

I have pin 21 and 42 connected to power (+14vdc) and pins 20 and 41 connected to ground. No joy on power up. Do I need 38 (power control)
Connected to ground? Am I missing something else?

Thanks in advance!
John

According to the installation manual, it depends on the connection of pin 59 (PWR CONFIG).

From the manual:

The PWR CONFIG input sets the remote on/off feature. This is connected to ground for a remote unit installation and not connected for a panel mount unit installation.

The PWR CONTROL input is dependent on the PWR CONFIG connection. This is used as a remote power on/off control or to use the power auto on feature when the avionics master is energized.

[von_flyer]

Thanks Ray.
I purposely did not connect the power control so it would not power up when the master was turned on, thereby being on while the engine cranked. Just looking for the ah ha before I crawl back under with meter etc.

[g3xpert]

Originally Posted by von_flyer

I have pin 21 and 42 connected to power (+14vdc) and pins 20 and 41 connected to ground. No joy on power up. Do I need 38 (power control)
Connected to ground? Am I missing something else?

Thanks in advance!
John

Hello John,

For a GTX 335/345 panel mount transponder for which you do not want it to automatically power up each time power is applied, you do not need to ground either pin 38 or pin 59 on connector P3251.

If you change your mind and want the transponder to come on automatically without pushing a button after power is applied, ground pin 38.

For remote mount GTX 35R/45R/335R/345R transponders, both pins 38 and 59 should be grounded.

Thanks,
Steve