Hello. I’m looking for pinout of back connector of Garmin 795. At “Bare wire” manuals I can see only colors but I havent original bare wire.
Maybe someone could just check where on this connector should be #1 RS-232 TX and RX by measuring original bare wire from garmin?
Thanks.
Which connector? Could there be something around here (Aera 660)?
RS232 etc is my day job and has been for decades. It is possible to work out the pinouts of a connector, with a bit of work, a voltmeter, and ideally an oscilloscope. If the connector is a DB9 then it is a lot easier anyway (basically two standards, unless Garmin have gone totally off-piste). To find a pin which is an output, get the box to emit something and see which pin it comes out on. You probably don’t need the input pin (it is for stuff like traffic, I think, which is not a big scene in Europe despite the myriad of handheld traffic gadgets). The ground pin is probably the connector body, or maybe whichever pin is connected to the negative terminal of the battery or the external power cable (I strongly doubt their RS232 interface is isolated/floating).
Hi. I mean this connector of aera 795. I havent bare wire but I can use unused pin’s on standard cable – is openable – enought just to swap some wires.
I need only RS-232 port, it would be enough for me to measure of original “bare wire” for 795 where is ended TX and RX cable (blue and yellow).
I would be amazed if you can find the mating half anyway – it is AFAIK a totally custom Garmin job, with nice spring loaded pins – so why not just buy the Garmin cable, like I did for the Aera 660? Much tidier. I am sure Peter Mundy will flog you one 
OTOH I may be misunderstanding your objective.
New bare cable is 100eur and delivery time. At this what I have I could only swap two pins in molex connector. It’s 5min job and 100% original quality.
Look photo.
Only I need for a moment original cable and measure where is RX and TX of rs-232 1 or 2.
Do you need input also, or just output?
Hi. I found output by analyzer. Its pin no 5 counter from right side when you look in connector of unit. Top is 1 bottom is 2. If you could check also RX and audio (L/R/common) would be great :)
There is no sure way to detect an RS232 input.
If done properly, there should be a pulldown to ground, and typically, depending on the chip used, say a max232 this might be 3k to 7k. This is a passive resistor so should measure that value with a DVM, with the unit unpowered.
So see which pins measure a few k to ground. Hopefully there will be only one.
Additionally, any such pin should not have any voltage coming out of it when the unit is powered up. Very unusually these days, there may be a pulldown resistor to say -5V.
The audio output on Garmin handhelds seems to vary. On the 496 it was a bridge output so you had two output pins, and when one went up the other went down. The intention was to connect a speaker across these, and there would not be a ground return causing trouble. The Aera 660 departs from that and has single ended stereo outputs (why stereo??)
What are you driving? A speaker of say 8 ohms?
