12V Socket, Possible Low Voltage?

[gary1208]

I have a 2006 Focus Titanium, the problem I have is that the 12v power socket doesn't seem to be supplying the full voltage, I have a brodit phone charger that charges fine in other cars but doesn't charge in my car. There is an power light on the charger which when plugged into my car flickers, but lights up fully in others.

I've only just found this out and it's a bit dark to check the fuse at the moment, but seeing as there is some power there I wouldn't think it would be that.

[artscot79]

inside the socket there are two flat bits of metal at the sides use something non metalic and slightly bend these in towards the inside of the socket mine did the same and these bits of metal were too far apart so there wasnt a proper connection

[stef123]

as above, it sounds more like a bad connection than low voltage

[NorthSussex]

It may be a poor connection in the socket, try a shot of WD40 in the socket. It’s unlikely to be the fuse. If that had gone you wouldn’t have any power to the phone, the other possibility is a poor connection in the wiring loom.

[gary1208]

I've been out and bent the tabs out, it's made no difference, I'll see if I can borrow a test meter from a friend during the week and go from there.

[stef123]

I've been out and bent the tabs out, it's made no difference, I'll see if I can borrow a test meter from a friend during the week and go from there.

is it possible to try another device/plug? it might be that its not touching the contact at the bottom correctly.

[rojariggs]

is it possible to try another device/plug? it might be that its not touching the contact at the bottom correctly.

Could well be this. You sometimes find that a socket is a slightly loose fit which, when combined with strong springs on a plug, forces it out of the socket enough to affect the connection.

Do you have (or can borrow) any other 12v accessories you can try in the socket?

[gary1208]

I've now tested the voltage in the socket and it reads 12.4v so that's fine, the charger works fine in other cars so I might look to replace the actual socket, does it just pull out or will I need to remove some trim from the console. Its just the normal 12v socket type, not cigarette lighter.

[NorthSussex]

Sometimes measuring the voltage with a meter can be misleading, as the voltage measured is not under any load. Before you change the socket it would be worth trying something else in the socket to see how that performs. If your car has more than 1 socket, as some models do, try that other socket.

[gary1208]

The charger is rated as drawing 2 amps and the socket is rated at 10 amps, but I'm thinking that its not supplying the proper current for some reason or other.

I'll borrow someone elses and see what happens, if that's the same it could be a trip to the garage.

[NorthSussex]

It sounds like a high resistance connection, most likely to be the socket. The socket should be cheap and easy to replace, I would try that first and try to save a garage charge, and one other thing to check is that the fuse feeding the socket has clean contacts.

[gary1208]

Fixed it! I changed the fuse for another one and it's now working fine, I also put the original one back in and it went back to its old ways, although the fuse looks fine.

[artscot79]

Weird that one never would have thought the fuse would be faulty

[NorthSussex]

Fixed it! I changed the fuse for another one and it's now working fine, I also put the original one back in and it went back to its old ways, although the fuse looks fine.

As I said, check the fuse for clean contacts, they can corrode and cause a high resistance under load.

Glad you got it sorted without the expense of a garage bill.

[Ian Gibbs]

Seconded here. I had the same symptoms of a socket that appeared to be working and presenting 12v when not under load, but only 7v when under load, and the same phone charger worked fine in the rear socket.

Turns out someone had fitted a special blade fuse that incorporates an LED that lights when the socket has blown (see attached image). Since it was bridging the blown fuse it made it appear as though there was voltage there, but any attempt to draw current through would be limited by the resistor in series with it designed to protect the LED, to probably a few milliamps. Replaced it with a new fuse and all is well.

[rhyds]

I had the same problem with a Land Rover Defender years ago. Bloke asked me to swap in a new radio (the old one apparently had "burnt out"). Head unit wouldn't turn on unless you hooked both feeds to the ignition switched side. In the end we traced the issue back to a duff glass fuse hidden behind the dash that was chopping the 12v feed down to 6v under load.