Turning on the rear camera automatically

[Snackchaser]

It seems like every time we really needed the rear view camera, we had forgotten to switch it on before leaving.  This modification turns the camera on automatically whenever the trailer is connected to the Tow Vehicle and the engine is running.  The main camera switch will also continue to work as normal if ever needed.

This is done by using an “Engine-on Detector Switch” that turns-on when there is an increase of voltage in the Tow Vehicles 12 Vdc charging circuit (Pin-4  of the 7-Pin wiring harness).  When the detector turns-on, it supplies 12Vdc to a solid-state relay, which then supplies 12Vdc to the camera.

The switch and solid-state relay are inexpensive, and the wiring is fairly simple.  However, this will only work on trailers with lithium batteries where the TV charging circuit is not connected.  This is typically the case for trailers with lithium batteries because they can draw more charging current than the wire is rated for.  In Oliver trailers with factory installed lithium batteries, the (Pin-4) charging wire is capped-off and sticking out of a wire bundle next to the inverter.  It’s a black #10 wire.

Start by removing the two small lag bolts holding the right side-board of the attic cabinet.  This gives access to the camera wiring, it’s a coil of small black jacketed cable with red and black wires.  A brown wire from the camera’s on/off switch is connected to the camera’s red wire.  From the same attic area, you can get a fish tape down between the walls and into the outside storage garage.  There is a clear shot from the right of the drain tube.  Pull a single new wire from the attic to the garage, then along the garage ceiling and into the area under the rear seat where the new switch and relay can be mounted.   One end of the new wire will be spliced into the brown wire from the camera switch, and the other end goes to the relay’s Normally Open switch.

Find the “spared” Pin-4 wire, as described above, and the new relay and engine switch can be mounted near by.  I attached my switch and relay next to my Starlink power supply and added a  brass strip as a ground bus.  However the relay and switch are small and they could mounted any number of ways.  See the sketch for wiring details.

Note:

1. The Engine-on Detector Switch and the relay is powered from the TV (Pin-4)
2. The relay powers the camera from the same circuit that it currently uses to prevent cross feeding of circuits.  In my trailer, this was the fuse labeled “Electronics” in the 12 Vdc fuse panel under the dinette.  I used a “Y” spade fitting to connect a new wire to the fuse in tandem with the existing wire, or they could be spliced together.
3. Both the relay and switch are connected to the negative ground bus under the rear dinette seat.

Amazon shopping list:

• IJDMTOY LED Daylight DRL Automatic On/Off Switch Controller
• ONO DPST 8 Amp Power Relay Module
• AIRIC 1/4 inch Split Cable Sleeve
• 36 Piece Electrical Spade Connectors (Auto part stores usually have them too)

I hope someone finds this useful

Cheers! Geoff

[MobileJoy]

Very clever @Snackchaser! Nicely done.

[Steve Morris]

Another cool project to add to the list! Thanks for documenting this. 

[SNY SD UP]

Geoff, this is a very interesting mod, and I can see others taking the  “Engine-on Detector Switch” concept for other projects.

For us at this time we are non-Lithium's so 'Turn On Rear View Camera' is on our 'Towing' checklist, just as 'Turn Off Rear View Camera' is on our 'setup' checklist.
I also verify it is on when I get to 'check out' Maggie, whilst we are are running thru the Rear (running, signal, brake, bkup, flashers) Lights sequence just before we start towing.

I will of course be following the feedback here.

B~Out

Edited September 2 by SNY SD UP

[Steph and Dud B]

Rearview Camera is on our pre-trip checklist:

RV Quick Checklist: 66 items shared

 

Monitors

□ 1 Change GPS to Movement/Daily

□ 2 Rearview camera on

□ 3 Install repeater

 

Bathroom

□ 4 Bathroom drain closed (in) & flagged

□ 5 Shower curtain secured

□ 6 Bathroom cabinet shut

□ 7 Bathroom window closed

□ 8 Bathroom vent closed

□ 9 bathroom items secured

□ 10 bathroom door closed

 

Interior

□ 11 Check ladder secure points

□ 12 Awning switches off

□ 13 Awning remote stored

□ 14 Microwave tray secure

□ 15 fan in fridge

□ 16 fridge doors locked

□ 18 Sink cover stored

□ 19 Stove off

□ 20 cooktop cover closed

□ 21 pots/pans/dishes

□ 22 furnace/AC off

□ 23 Marine fan stowed

□ 24 roof vent closed/fan off

□ 25 Remotes stored

□ 26 antenna booster off

□ 27 AC alarm off

□ 28 TVs secured

□ Solar on/off

□ 29 Gas water heater off

□ 30 water pump off

□ 31 weather radio off

□ 32 Xantrex setting #28 to 5 (storage) or 25 (camping) or 15 (generator)

□ 34 tires checked

□ 35 doors/drawers/windows closed

□ 36 blinds closed

□ 37 Cabin lights off

 

Exterior

□ 38 LP gas off

□ 33 thermometer stored

□ 39 Electric water heater off/on

□ 40 sewer hose secured

□ 41 tire covers off

□ 42 leveling jacks up

□ 43 water/elec./TV/sewer d/c

 

Truck

□ 44 Close tailgate

□ 45 bikes secured

□ 46 Wheel step removed

□ 47 Ball hitch pinned and locked

□ 48 parking brake set

□ 49 Chains on

□ 50 breakaway cable

□ 51 Coupler pinned

□ 52 Tongue jack up

 

Hitched

□ 53 vehicle lights checked

□ 54 wheel chocks out

□ 55 Linx levelers stored

□ 17 fridge on 12v

□ 56 door mat stored

□ 57 doors/compartments locked

□ 58 steps retracted

□ 60 trailer transponder in

 

Mechanical

□ 59 trailer brakes checked

□ 61 radiator clear

□ 62 washer fluid checked

□ 63 ATF checked

□ 64 brake fluid checked

□ 65 coolant checked

[Ronbrink]

@Steph and Dud B, you are CLEARED FOR TAKEOFF!

[topgun2]

1 hour ago, Ronbrink said:

you are CLEARED FOR TAKEOFF!

Which runway?😗

[Ronbrink]

31 minutes ago, topgun2 said:

Which runway?😗

The one that leads to their next adventure!

[topgun2]

3 hours ago, Ronbrink said:

The one that leads to their next adventure!

That'll work.

[jd1923]

15 hours ago, Snackchaser said:

This is done by using an “Engine-on Detector Switch”

Useful idea, great plan with drawing and knowledge of relay wiring! And thank you for showing all the camera wiring too, very helpful!

Wondering if instead of this switch, could the same relay read power from the trailer 7-blade hitch connector? The black wire shows 12V+ while connected. Oliver disconnects it from the +bus for LiFePo4 installations, but if so, it is likely capped and laying below on the basement floor. It's the black wire you see in my picture when I disconnected it in our older hull. Wiring in new hulls is likely different.

You could instead pick up the feed from the yellow wire for the reverse lights, but the camera would turn ON/OFF switching in and out of reverse.

[Snackchaser]

2 hours ago, jd1923 said:

Wondering if instead of this switch, could the same relay read power from the trailer 7-blade hitch connector?

 

Yes you could wire the relay coil directly from the “7-blade hitch connectors” 12v+ black wire (Same wire I referred to as Pin-4).  However this wire becomes energized when the hitch connecter is plugged into the TV, running or not  This creates a parasite drain from both the relay and camera that could rundown the TV battery if left connected for long periods.  If you were to do this, remember to unplug and use the Solid State Relay because of their low power consumption.

For similar reasons, this modification won’t work if pin-4 is connected to the trailers battery charging system, such as with lead acid batteries, because Pin-4 is always energized either from the trailer battery or the TV charging.

Good idea for the reverse wiring, if you only use the camera for backing up.  We mostly use the Oliver camera for checking the bikes.  We have another high resoulution camera that displays on the TV rearview mirror that we use for backing up and lane changing.  It's an awesome feature for towing. 

Cheers, Geoff