26 replies to this topic

[IainNeon91]

Hi all,

 

I've just changed the fuse box on my mini and now the ignition light & Oil pressure light are constantly lit up...?? I thought that i had just put the wires in the wrong order on the fuse box but the lights still stayed on once i had disconnected all the wires from the fuse box...??

 

I started the car, started fine, then went to turn it off, took out the keys and the car kept running!? Only way i got it to stop was to take off the coil wire.

 

I have now disconnected the battery as this was the only was to turn off the ignition... Just so it doesn't drain all my power...

 

Any help would be great!!

 

Many thanks,

 

Iain.

 

P.s. I will try and get a couple of videos up to show you.

 

[tiger99]

You have a stray connection between a brown or purple wire, both of which are permanently live, and a white or green wire, which are downstream of the ignition switch. I would check the fusebox connections again, and the ignition switch terminals.

[IainNeon91]

 

 

Video links

[IainNeon91]

i don't understand how the lights can stay on with none of the wires connected to the fuse box though??

 

I did get suggested that there is a broken earth somewhere...?

[Ethel]

Possibly a dodgy alternator. The printed circuit on the back of the dash can all do funny things if it gets wet, but I can't think how that would bypass the ignition switch.

[IainNeon91]

Specifically what could be 'Dodgy' about the alternator?? The live wires on the side??

 

Yeah... I didn't notice that the lights where on before i touched anything... But my battery would have been dead... I haven't ran it in two days

[Ethel]

The alternator has a permanent live connection to the battery, turning on the ignition just provides an "exciter" current to get it started at producing power when it spins. an internal fault (such as a blown diode) can allow it to conduct when it's not turning. Though it could just be a short as well.

 

The resistance of the warning bulbs is pretty high, a charged battery could keep them lit for days.

 

A clue may be the brightness increasing when you turn the ignition on, if the current is coming from the alternator alternator the bulbs would be in series before the oil switch earth.

[tiger99]

The live feed to the ignition switch does not go via the fuse box on many Minis, but direct from the battery terminal at the solenoid, so will still be live when the fusebox wires are disconnected, so a short at the switch will make it run continuously. The alternator feeds the main battery terminal of the solenoid by a seperate brown wire, or pair of wires, again not routed via the fuse box.

[IainNeon91]

So what would you suggest i check/do??

[tiger99]

Just do as I already said, and check that there is no contact between any brown wire and any white wire, especially at the ignition switch. It can only be a short of some kind, not an alternator or earth fault.

[dklawson]

Since you removed and reinstalled the fuse box, do as Tiger said and look carefully at the fuse box and your car's wiring diagram.  You are likely to have accidentally connected a white wire to a shared/common terminal with a brown or purple wire as he said.

 

We just went through a very similar troubleshooting thread on Mini Mania.  The OP had also worked on his fuse box and made a mistake reconnecting the wires. 

 

EDIT.  Specifically look at the BACK of the fuse box.  I believe you'll find a couple of terminals are jumpered together.  You may have installed your new fuse box rotated 180 degrees and accidentaly selected terminals that are joined when reattaching your car's wiring.

Edited by dklawson, 24 January 2014 - 04:22 PM.

[Ethel]

The obvious thing is to unplug the alternator and see if that puts the lights out, if it doesn't you'll be hunting down that short. While it's true the ignition circuit isn't fused it does have connection on the upstream side of the fuses, as do those permanent (brown & purple) feeds.

 

Make sure there are no whites or greens connected anywhere on the same fuse as a brown or purple.

[IainNeon91]

I just check the ignition switch and it doesn't seem like there is a short at that end... Where would the next place in the circuit be??

[tiger99]

It can't be the alternator, as back-feeding via the ignition warning lamp, the only possible path, would not pass enough current to keep the engine running.

[IainNeon91]

Since you removed and reinstalled the fuse box, do as Tiger said and look carefully at the fuse box and your car's wiring diagram.  You are likely to have accidentally connected a white wire to a shared/common terminal with a brown or purple wire as he said.

 

We just went through a very similar troubleshooting thread on Mini Mania.  The OP had also worked on his fuse box and made a mistake reconnecting the wires. 

 

Once you have eliminated the fuse box wiring as a problem THEN you can look for other sources if necessary.

Here's a picture of how it's wired now...