Electrics problem - "light on" warning and rear fog

[JS2004]

Hi all,

 

Hopefully someone can help as I have just made the situation worse trying to sort it myself!

 

Problem outline:

Rear fog light controlled by switch on steering rack - it stopped illuminating to indicate "ON". It would work sometimes but stopped working. I have MOT coming up, decided to fix before MOT.

 

Went to maplin to obtain switch - 3 prongs, rocker switch.

 

Removed old switch, noticed only one of the prongs was connected, but three wires with connectors were available.

 

I have traced the three wires.

 

Wire 1 - This connects to the "gold" part of rocker switch, goes to the rear fog light.

 

Wire 2 - Looks to be a feed from the "Live" wire that supplys the ash tray internal light

 

Wire 3 - I can only assume this is the earth, comes from the other wire that supplies the ash tray internal light.

 

I had a little multimeter on these, one wire *Was* reading 12v. (Assuming this is the live). The other wire was nada.

 

I connected both these to the rocker switch which made it illuminate when on, but now its stopped. I think I may have reversed the connectors initially. The light on the switch no longer works with any combination.

 

I do not appear to have a 12v live wire any more - either multimeter is on blink or ive broken something.

 

The ash tray light doesnt work but I am going to get a replacement bulb so that I can tell if this feed is live or not.

 

 

Now to make things worse- the rear fog light now doesnt work.

 

Additionally.. the warning siren that sounds when you take keys out of ignition and leave the lights on has stopped.

 

Help I have a basic electrical understanding but just want the rear fog back for MOT. I am copntemplating removing the dash to get at cigarette lighter feed. However I am really confused why the warning siren has stopped when I leave the lights on. It still does the intermittent warning sound - but not the constant one when lights left on.

 

Thankyou

[merckx]

Rear fog light controlled by switch on steering rack -

 

I'll start by saying, you must have long arms.

 

Didn't you want to clutter the dashboard with a horrible aftermarket switch?

 

 

If you bought a 3 prong terminal illuminated switch then you've probably bought the correct one. (You can also buy 3 terminal switches that are single pole/2 way which you wouldn't want).

 

These 3 terminal switches aren't designed to illuminate when the dashboard is lit up at night(4 terminal one) so I wouldn't connect it up to the ashtray illumination wire as in theory it might work but you could easily overload it and blow the fuse . (I'm not sure of the fuse size).

 

 

Did you identify the terminals on the new switch, it looks to me that you may got them mixed up and have blown the fuse for the ashtray?

 

 

The 3 terminals on the switch should be labelled:

 

1.Earth............. Connect it to a good bare metal earth somewhere around the centre console.

 

2.Load...............Connect this to the foglight. (The other connection at the foglight itself should be earthed).

 

3.Supply............

 

Connect this to a 12v supply that becomes live when the ignition is on (This is obviously to prevent the battery from being drained if you connected it to a permanent live and forget to switch the foglights off), also fit an inline fuse. Don't forget you're adding an extra load to an existing circuit that supplies something else so make sure it's man enough. (The ashtray illumination isn't).

 

I can't remember which 12v supply I used last time as it's a while since i worked on the electrics, I vaguely remember using a supply in the drivers footwell which was there for heated seats which I don't have.

[Suprab1]

My Supra doesn't have an alarm for lights, they just turn off when you open the door to get out.

[Suprab1]

Hi mate, my Supra doesn't have an alarm to let you know the lights are still on, they just turn off when you open the door to get out.

 

Sorry for double post, my internet is playing up.

Edited February 22, 2010 by Suprab1 (see edit history)

[JS2004]

Thanks for replies so far guys.

 

Suprab1 - the bit im worried about with the alarm is that it worked right up to the point I started fiddling with wires - however I have now rectified this via breaking my back to get at drivers side footwell fuse box! (Why it was put there ill never know).

 

Merckx - I meant streering column I think lol its just on the side below the light stalk. It was there when I bought it, I would have preferred it on the dash itself.

 

Since writing the post I have been out there messing. Replaced one fuse in drivers footwell that was blown. Also replaced the actual bulb (its in the drivers side reverse light). I additionally put a new bulb in the ashtray as I wasnt sure if that supply was working. The new bulb is a LED one.

 

Current situation =

 

Ashtray light illuminates when sidelights etc on.

 

Used what I think is the live from ashtray into the aftermarket switch. The switch now illuminates when in the "On" position.

 

Now it gets confusing here...

 

Firstly I have the 2nd line coming off the ashtray light which I assumed was an Earth but now I am not sure.

 

When I put the sidelights on only, and then switch the foglight switch to "on" the rear foglight comes on (regardless if front fogs are on or off). With just sidelights switch works as intended and rear fog can be switched on and off happily.

 

When I put sidelights on, and then rear fog, and then go to dipped / full beam.. the rear fog stays on until i turn it off via the switch, at which stage it no longer comes back on (but the switch still illuminates correctly).

 

When I put sidelights and then dipped beam on (or full) and then attempt to turn rear fog on, it will not come on.

 

It seems to need a little time in between to "reset" before the above sequence works. It doesnt seem right.

 

Currently as it is only connected to the ashtray light I think it shouldnt drain the battery as this only comes on when sidelights or more are switched on.

 

I will try to fit an inline fuse - not sure how to at the moment though.

 

Im just a bit confused now because the rear fog light works but only if I do a certain combination.. its a bit like a puzzle.. but obviously I dont want the puzzle want it to work without messing around ..

[JS2004]

To recap on this - It failed MOT as the LED light that *sometimeS* lit up with fog switch on wasnt bright enough. It wont light a normal bulb.

 

Have got the whole dash out at the moment trying to rectify it. As you pointed out the ashtray supply isnt good enough - it never had a bulb in so im not sure if whats happening now was happening before - but basically..

 

Lights on = ashtray light on

Lights on + fog light switch on = ashtray light dim, occasional smoke from behind dash..

 

Theres definately no inline fuse ive had the wiring out for the fog light switch itself. I am currently in the process of following Homers "Simple fog light mod" and trying to re-route it to use the Dimmer switch live..

 

I have an auto-electricians number which I will be calling out soon I think.. The smoke and stuff coming from behind the dash, and the ashtray light dimming itself has me quite worried. If I had blown a fuse surely the ashtray light wouldnt come on - but im not sure if that light is controlled by a fuse or not - im off out there to start pulling fuses and seeing what turns off.

 

All this for a fog light I probably will never even use as I dont take her out when conditions are not nice.. but I suppose its for the one time the fog catches you =/