Dashcam Powered from 3 pin Rain Sensor

01-21-2026

I have powered my Nextbase Piqo 2k dashcam using the Mangoal 3pin rain sensor adaptor.

The install is very clean and avoids having to route a wire to the fusebox. The problem I am having is that the dashcam is powering up even when the car is locked and "sleeping". The rain sensor is supposed to be a switched live but the dashcam is powering on randomly, sometimes recording for an hour or more. The only way I have been able to prevent this is by enabling the dashcam parking mode which puts it into hibernation mode and setting the sensitivity level at low.

Has anyone else who uses the 3 pin rain sensor adaptor encountered this rogue powering up?

01-21-2026

I tried the Mangoal adapter with a Viofo dash cam and had issues as well. It would randomly turn the dash cam on and off and never shut off after the vehicle was locked. I ended up returning it back to Amazon and got the Dongar adapter.

The Dongar adapter is better but not perfect. Dash cam turns off after about 5 minutes after locking the car but would also randomly wake up and power the dash cam for a few minutes before shutting off on days I didn't go out. It also triggered a 'battery management warning', probably because it detects a battery drainage from the adapter being constantly powered on.

I am going to wait and test it out for a few more days before I switch to the fusebox hardwire option.

An image attached to this post, provided by the poster

01-21-2026

ZCPM3 wrote
I tried the Mangoal adapter with a Viofo dash cam and had issues as well. It would randomly turn the dash cam on and off and never shut off after the vehicle was locked. I ended up returning it back to Amazon and got the Dongar adapter.

The Dongar adapter is better but not perfect. Dash cam turns off after about 5 minutes after locking the car but would also randomly wake up and power the dash cam for a few minutes before shutting off on days I didn't go out. It also triggered a 'battery management warning', probably because it detects a battery drainage from the adapter being constantly powered on.

I am going to wait and test it out for a few more days before I switch to the fusebox hardwire option.

Thanks for the info. I think the circuitry in these adaptors probably cost a few pennies and I’m probably expecting and relying too much on it!! I think I am going to return the adaptor too and revert to routing a cable to the fuse box. Let me know if you have any luck with the Dongar.

02-12-2026

I finally had the chance to hardwire my Viofo dashcam with their hardwire kit. I added fuse taps to fusebox located on the passenger footwell. F27 for constant battery power, F72 for switched accessory, and the grounded the nut below the glovebox.

If I lock the car, the dash cam will power off after 6 minutes. As soon as I unlock it, it will power on the dash cam. So far so good. Fingers crossed no more battery warning.

Gonkface wrote
Thanks for the info. I think the circuitry in these adaptors probably cost a few pennies and I’m probably expecting and relying too much on it!! I think I am going to return the adaptor too and revert to routing a cable to the fuse box. Let me know if you have any luck with the Dongar.

02-12-2026

Having the same problem with the mangoal adapter. won't shut off, random power cycles, etc.

just ordered Viofo's hardwired kit , will install this weekend

02-12-2026

ZCPM3 wrote
I finally had the chance to hardwire my Viofo dashcam with their hardwire kit. I added fuse taps to fusebox located on the passenger footwell. F27 for constant battery power, F72 for switched accessory, and the grounded the nut below the glovebox.

If I lock the car, the dash cam will power off after 6 minutes. As soon as I unlock it, it will power on the dash cam. So far so good. Fingers crossed no more battery warning.

I ended up going with a slightly different approach. I routed a usb cable from the dashcam around the headliner, down the pillar across the footwell and then under the centre console trim to the split armrest usb c. I'ts not as clean as wiring it in to the fusebox (which I may still do) but it at least shuts down and does not randomly switch itself on they way it did with the Mangoal.

Quick quesiton on your fuse choice. You say that you fusetapped in to 27 for constant power and 72 for acc power. I presume your dashcam has a parking function necessitating the need for the constant power? I have no need for that so I am thinking that I would simply use the 72 and ground?

02-12-2026

seabag wrote
Having the same problem with the mangoal adapter. won't shut off, random power cycles, etc.

just ordered Viofo's hardwired kit , will install this weekend

Yeah, the promise is great but the reality is rubbish. They advertise as using acc only but that's not the case. Shame too cause it was a really clean way of doing it and very easy to install.

02-13-2026

Gonkface wrote
Yeah, the promise is great but the reality is rubbish. They advertise as using acc only but that's not the case. Shame too cause it was a really clean way of doing it and very easy to install.

what's funny is that I have my radar detector wired to the rear view mirror power. that behaves as expected, so for some reason the rain sensor behaves differently

Yesterday

seabag wrote
what's funny is that I have my radar detector wired to the rear view mirror power. that behaves as expected, so for some reason the rain sensor behaves differently

Sorry to revive this post from the dead, but thought to share what I found in trying to use a Dongar on my G29. This could explain the behavior you folks are seeing. This post from the G60 forum says the same too.

From what I can tell, the rain sensor on G-series cars is powered from Terminal 30F, which supplies control units that carry out functions in the condition "Parking". It's is generally switched on when the car is parked. Terminal 30F may be switched off due to faults in the vehicle electrical system. If a fault is detected, it is switched off with an after-running period of 1 minute.

The rearview mirror, is powered from Terminal 30B, which supplies control units which are needed in the stationary mode condition "Residing" and for stationary functions for which the driver is not present in the vehicle. During the transition from "Residing" to "Parking", an after-run of 3 minutes starts. Terminal 30B is subsequently switched off. The rain sensor on F-series cars was tied to this bus.

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Dashcam Powered from 3 pin Rain Sensor