Help with Pinout

[hkyfrk]

I installed a wireless backup camera on my car and I am up to the point of hard wiring the receiver in the dash. Is there any way using my multimeter to find out on which part of the 2.5mm jack is the video signal coming in on? The wireless receiver (the part that goes into my gps unit) has a 2.5mm jack and I need to convert to a 3.5mm. The Camera is powered and Video is supplied when I put the car in reverse.
Thanks

 

[Harvey]

Are you talking about a connector that looks like a stereo connector with tip, ring and sleeve contacts like this?

If so, the sleeve is usually (but not necessarily) ground, and the manufacturer could use either of the remaining two for power and signal.

I strongly recommend contacting your camera's manufacturer for info. With any luck, they'll have a site with a link to documentation for your model or at least tech support link or an e-mail address where you could request info.

If the pinout is the same as for the 3.5 mm jack, you can use a 2.5 mm -> 3.5 mm adapter like this.

 

[hkyfrk]

Thanks for your help...
I plugged the receiver in to give it power using it's USB plug. I put the black probe on the sleeve and the red on ring #3 (it's a 4 conductor) and I got 5 dc volts. When I put the probes black on 3 red on 4 the needle wanted to go the other way (-). Does this mean that the video signal is coming thru on ring #3 and 4 is ground?

 

[Harvey]

I don't know the pinout of that device. It wouldn't suprise me if it has separate ground returns for video signal and power. Again, check with the manufacturer for a definitive answer.

Good luck.