Back-up switch question

[mthomas58]

Will be installing a back-up camera that will feed to my Nav screen soon so I need to find the best location to tap into the back-up light circuit.

Is the switch on the tranny on the (-) ground side or (+) side of the circuit? Thought I'd run across the answer on a thread but could not find with a search

I'll need to tap into the (+) side to activate the camera. Best location will probably be at the tail light.....but I'll need run a lead to the Nav dock in the trunk.

Any chance of finding a hot "switch activated" tap location in the trunk?

Thanks!

[boyt911sc]

Mark,

If your '87 has similar wiring diagram to early Carrera or SC's, the're many connecting points in the trunk you could tap power: (a). Ignition switch OFF: fuses for interior lights, and warning light for heated windshield. (b). Ignition ON: There several points, fuses for bak-up lights, air blower relay, sunroof, windshield wiper, cigarette ligther, and fuel pump relay. Use a test light and you'll find these points.

The 915 trans back-up light switch is a ground (-) contact switch. The 3 fuses at the rear are also a good source for power. Hope this will help you.

Tony

[mthomas58]

Tony, thanks for the suggestions and confirmation that the back-up switch closes the ground. Finding a power source in the trunk is not a problem......what I need to find is a back up switch powered circuit to trigger the Source Selector on the LCD Screen from Nav to Back-up Camera when I shift into reverse then back to Nav when out of Reverse. Not sure if tapping into the low side of the back-up light circuit fuse will work????

[euro911sc]

Just out of curiosity... do you actually have trouble seeing back there? Or is this simply a neat gadget exercise?

-michael

[mthomas58]

Originally Posted by euro911sc

Just out of curiosity... do you actually have trouble seeing back there? Or is this simply a neat gadget exercise?

-michael

Both but clearly more of a gadget excercise since the nav screen has video camera input.

[boyt911sc]

Originally Posted by boyt911sc

The 915 trans back-up light switch is a ground (-) contact switch.

Tony

Mark,

I gave you the wrong information about the back-up ligh switch. The 915 back-up light switch (F4) carries power from the ignition switch to the back-up lights. So F4 (back-up light switch) is a + on/off switch for power not ground as previously stated.

I'm surprised nobody noticed the error. Sent PM too.

Tony