mokes

Odd dashcam issue related to key position.

Recommended Posts

I installed my dashcam using a hardwire kit and it all seemed to work fine when I checked it after install ( the first one blew up on first switch on).

Today I noticed that it wasn't on when I was driving and doing some checks showed that it turns on with the key, as planned, but as soon as the key is turned all the way to 'start' it turns itself off.

If I turn the key all the way to 'start' without pausing the dashcam turns on and stays on, as planned. If I put the key in the postion just before 'start' ( because I'm sat waiting in the car and want to open a window or whatever), the dashcam comes on ( as planned) but if ITHEN carry on to start the engine a few seconds later, the dashcam turns off.

I have the same dashcam in my other car, in which the ***** lighter goes off with the ignition, so I just leave the supplied power cable in the ***** lighter all the time. It come on when I turn the key and goes off when I take the key out. The Focus isn't like that , hence the hardwire kit.

Any sparkys out there know whats going on?

Share this post


Link to post
Share on other sites

Did you take the tap off of the ignition feed?

It's best to come off a connection that isn't linked to any engine or ignition circuits like rear wiper or suchlike.

 

Sent from my SM-G965F using Tapatalk

 

 

 

 

Share this post


Link to post
Share on other sites
5 hours ago, mokes said:

If I turn the key all the way to 'start' without pausing the dashcam turns on and stays on, as planned. If I put the key in the postion just before 'start' ( because I'm sat waiting in the car and want to open a window or whatever), the dashcam comes on ( as planned) but if ITHEN carry on to start the engine a few seconds later, the dashcam turns off.

If it is connected to a circuit that comes live with the key in the Aux (1st) position, like the radio / audio circuits, then that circuit goes dead when the key is turned to Start. It should come back on again when returned to the normal Ign (2nd) position though. So it sounds like the sat nav does not like a brief power interruption just after boot-up, and fails to boot-up again. This is quite common, power supplies and processors in equipment sometimes need to fully shut down, with all internal voltages decayed, before they can start up again. And it can be variable depending on tolerances, so equipment can behave differently even though nominally the same.

If the sat nav is on an Ign feed (not Aux), then it could be it does not like the low voltage that you get when starting. Check the car battery to see if it is dropping badly when cranking.

So if it is wired to Aux, try it on an Ign circuit, and if on Ign, try it on Aux.

Share this post


Link to post
Share on other sites

Ok, I'll check which it is and swap it about. I connected it to the rear wiper circuit, as it is the easiest fuse to get to and shuts off when key is off, so seemed to work as intended. battery was reading fine when I last checked it a month ago, no discernable issue with voltage drop on start.

Still not sure why the dashcam works fine ONLY if I go straight to 'ignition start' position though?  

Share this post


Link to post
Share on other sites
5 hours ago, mokes said:

Still not sure why the dashcam works fine ONLY if I go straight to 'ignition start' position though?  

When you go straight from off to start, it does not have time to power up before the voltage drop for starting. It seems that then when it gets, full, undisturbed power, it can boot up ok.

The rear wiper fuse (F131, or F78 in the older fuse box) is Ignition supply, via a relay (R8, called Ignition overload relay) in the front fuse box. This relay supplies several less critical circuits that are not required while starting, and is software controlled, so I am not sure if it remains on during cranking. Fog lights & Reversing light as well as rear wiper. If fog lights go out while cranking, then the rear wiper circuit will also go out. It is not something I have ever checked!

There are several direct Ign fuses (not software controlled), F100 (F70 in the older box) is the most commonly used one.

Share this post


Link to post
Share on other sites
55 minutes ago, Tdci-Peter said:

When you go straight from off to start, it does not have time to power up before the voltage drop for starting. It seems that then when it gets, full, undisturbed power, it can boot up ok.

The rear wiper fuse (F131, or F78 in the older fuse box) is Ignition supply, via a relay (R8, called Ignition overload relay) in the front fuse box. This relay supplies several less critical circuits that are not required while starting, and is software controlled, so I am not sure if it remains on during cranking. Fog lights & Reversing light as well as rear wiper. If fog lights go out while cranking, then the rear wiper circuit will also go out. It is not something I have ever checked!

There are several direct Ign fuses (not software controlled), F100 (F70 in the older box) is the most commonly used one.

Are you referring to the Jcase fuses? I think they have delayed startup to avoid the voltage spike when you turn the engine over, this would be an ideal circuit for a dash cam.

Share this post


Link to post
Share on other sites

F100 is one of the ordinary mini-fuses in the passenger fusebox.

The bigger Jcase fuses in the engine fusebox have a time delay to blow, or anti-surge capability, but I don't think they have much effect on removing current surges or voltage spikes from the supplied circuits, the delay is to prevent spurious trips (fuse blowing) due to brief surges.

Share this post


Link to post
Share on other sites

Ok. I'll try F100..see what happens. Either that or always start straight off, which I do 99% of the time.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.