Source of delayed-off +12V behind or around the dash

**101RRS** · 27th March 2021, 12:10 PM

So why do you want to have power to your dash cam for just a few minutes after you switch off.

When I did mine I had trouble finding normal switched power up in the overhead console as it was all delayed in one form or another. In the end I used a piggy back fuse off the main switch board and ran straight switched power to the overhead console with a cig socket - and used a standard 12v-5v usb plug to provide power.

If you want your dash cam to pick up "problems" while you are away from the car then as Tombie suggested us the correct power kit for your Dash Cam that allows you to do that.

Cheers

Garry

**BradC** · 27th March 2021, 12:31 PM

Originally Posted by 101RRS

So why do you want to have power to your dash cam for just a few minutes after you switch off.

Can't really answer that other than it seemed like a good idea at the time. This dash cam isn't clever enough to have a parking mode.

Once I have the cable up there with the additional power sources I can just make it up as I go along.

**BradC** · 28th March 2021, 07:59 PM

So I "made it up" and decided after playing with a number of time delays that it's just not worth farting around.

On the upside, we now have wireless carplay on the stock screen, so it hasn't entirely been a wasted effort. Now I just need the steering wheel buttons to arrive..... yay covid shipping delays.

**ChookD2** · 28th March 2021, 09:48 PM

I have been messing around with the power supply for my UHF recently. Had it straight off the battery and a 1hr timer set in UHF.

But I prefer it to come on and off with ignition so started poking around in engine bay fuse box using one of these.

Eventually I found fuse number 9, which in my case was vacant (D3 V6 Petrol), comes on after system check with ignition and remains on when key removed for perhaps 1+ mins.

Don't know if that helps.

**BradC** · 20th April 2021, 11:57 PM

Originally Posted by ChookD2

I have been messing around with the power supply for my UHF recently. Had it straight off the battery and a 1hr timer set in UHF.

But I prefer it to come on and off with ignition so started poking around in engine bay fuse box using one of these.

Eventually I found fuse number 9, which in my case was vacant (D3 V6 Petrol), comes on after system check with ignition and remains on when key removed for perhaps 1+ mins.

Don't know if that helps.

Actually it does. That sent me off on another trawl of the wiring diagrams.

Fuse 9E was for Active Roll Control (up to 2005). Checking the wiring diagram, Fuse 9E is supplied from the "Relay-Engine control module" R116 along with a plethora of other fuses in the engine bay. It also supplies 2E (Active leak detection in North American models) and 6E (Ignition coils in the Petrol). 2E should be free in yours also.

I've also contemplated using CJB Fuse P40 (Key in sense) or fuses P9/15/22/24/25/28/35/37/36/62/64/66 (Ignition) as a trigger to a secondary relay. I've already used CJB P6 as the reverse sense/camera power (that's relay switched trailer socket reverse).

I currently have things on the Aux circuit, but that seems to drop power while cranking, so I'm tossing up between ignition or key-in. This is not so much for the dash cam but the carplay/handsfree mainly. On further checking, it would appear ignition is available at the switch module above the radio (C2387 pin 12), for the TPMS (which I don't have) and is on a dedicated 5A fuse which is therefore unused in mine, so I might grab that. The total draw for the Carplay/GVIF/Dashcam is under 2A worst case.

**p38arover** · 21st April 2021, 07:32 AM

Jaycar will have what you need, e.g., Short Circuits Two Project - Countdown Timer | Jaycar Electronics

**Tombie** · 21st April 2021, 08:26 AM

Have a look in the “What did you do on your D3/4 thread”

A PDM60 will do everything you want and more.
Not a cheap solution but very configurable

**BradC** · 21st April 2021, 12:09 PM

Originally Posted by Tombie

Have a look in the “What did you do on your D3/4 thread”

A PDM60 will do everything you want and more.
Not a cheap solution but very configurable

I did see that. For what I want it's a bit like cracking a walnut with an extremely expensive sledge hammer.

I think I've decided to use the "Key-In" signal (but I reserve the right to remain indecisive). The handsfree relies on the audio system, and the audio system comes on when the ignition is switched to Aux and off when the key is removed. I can't fathom any scenario where I'd put the key in and not turn it, and I certainly want it to remain on until the key is removed. I could use a relay and pair of diodes to get "Aux on / Key-out off", but for the purpose I can't see any advantages of that over "Key-In On / Key-Out off". Because of the low current draw of the gear (< 2A) and the plugs I've already got in place, I should be able to get away with an "add-a-fuse" on fuse 40P. The wire to the ignition switch is a 1.5mm2, so I'll take a chance that the switch contacts can cope with a ~1.5A load (they are currently only used for a logic signal to the CJB and Park brake module).

Because the dash cam has a super-cap in it, it has no problem riding over the crank period, so I can leave that as-is.

Edit: Yep that did the job nicely.

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