I have been using the cigarette lighter socket for my SatNav but its stopped working. 

Thought it might be the fuse but the handbook says it is 24 and there is no fuse in that slot . I do not appear to have power socket in the boot but there is a fuse in the designated slot (26) which is OK . My car is an Octavia Elegance 2012. Any thoughts.

Check all of the fuses, the lhd Octavia is notorious for not matching what the handbook says.

Only the estate has a socket in the boot. Have you tried plugging anything else into the 12V socket?   A comma "gotcha" is that the fuse in the pin of the plug has blown.

Thanks .Nothing works in the lighter socket and the  satnav works in other cars. Did not know that there was a fuse in the socket.

can not see anything so how do you get at it.?

Stan 80

There are many variants of the plug and it also depends on the cable size. Electrical engineering practice (as defined in the regulations), require that to avoid fire risk, when you go from a large capacity source to a small consumer where the cable is sized for the consumer load current, that a fuse be placed before the cable so that in the event of a short, the cable is protected by the smaller fuse. 

You do not need a fused plug if the cable is sized for the max current provide by the upstream fused supply, usually 10A but can be higher.

 

In the case of car power plugs, the fuse in the pin is accessed by unscrewing the pin end of the plug. the fuse is often a small 1A glass fuse but can be greater depending on the size of cable.

 

You can perhaps see from this approach why you should never connect anything directly to the car battery as the fault current will overheat your cable if the cable insulation is rubbed through and shorts to chassis. That is also why our cars have spare fuse places in all fuse boxes so that you can add an additional fuse for your new audio base amplifier,  relays, extra lights, communication equipment etc.

Thanks

will look at the plug but don't think it's fused . Looks like I will have to check all the 10 and 15 amp fuses in the cabin fuse box

Stan 80

My power socket lost live feed when it got shorted by a plug that fell apart causing a spark, I found the fault was a fuse located in the area to the side of the dash by the drivers door. There are 2 fuses numbered 25 from memory and it was one of those that had blown.

Thanks I have checked the side panel fuse box .The problem is that there is no fuse in the slot that the handbook says is the one for the cigarette lighter . It can't have fallen out and as as the lighter socket was working previously it must be fused from a different slot which I am trying to track down.

Stan 80

What model year is your car. Pre facelift models had a 25A fuse in position FS 24 for the cigar/ power socket (and so always needed a fused plug). I will edit this if I find a different fuse position for later models, as seems likely from what you said.

 

In the meantime, you could take out each fuse in turn and check them with a multimeter on the ohms or continuity range. Although in theory you can a find a blown fuse by looking at it, small overloads sometimes blow the fuse with just a hairline crack, hence the need for a continuity test.

 

Edit. One final thought is that the socket has failed. In fact I have to twist my plug around in the socket sometimes to make contact. There is a post in this forum somewhere showing how to change it. Needs a search.

 

 

 

Edited 12 November, 20178 yr by pikpilot
Last para added

Many thanks? My car is a 2012 elegance . The handbook says the fuse should be in F24 but it's empty.There is a fuse in slot 26for the 12 volt auxiliary socket in the boot ( which is not fitted in my model ) so checked that and it was OK. Will check all the other fuses although they look OK. Could well be the socket itself and will look more closely at that.

Stan80

Hi .was this fixed because i have same problem  no power to 12volt cigar lighter or socket in boot.

I have checked fuses and are all ok..

Is there a relay in fuse box in engine compartment ?

Cheers