headlight problems

[richrx]

i did that with mine - added 12v to the wrong place and cooked the switch

how long did it take you to solve before wanting to burn it... err hi mr insurance, it must have been an electrical fault that caused the fire:flamed


richard

[Prof]

those readings sound about right.
 
The 4v on BG is possibly a bit odd - that wire goes to the fog light relay and also the dip/dim relay.  You could unplug both of those relays - the fog light relay is in the front of the car (in the batch in front of the radiator) and the dip/dim relay is a small grey box behind the glove box - mine was easy to find as it was dangling down
 
With both unplugged there should be nothing on that wire if the switch is unplugged as well.
 
As to the pop up\'s.  On the UK car this a wierdly complicated circuit that operates the pop ups.
 
Inside the switch, there is a small relay operated by the headlight switch - it\'s wired in with the maintenance switch (in series).
 
Basically when the lights are off, 12V from the red wire passes through the relay contacts to the switch - and it can feed either down or up signals - so you can raise and lower the lights.  When the lights are turned on, the relay contacts switch over - now only the up signal has 12v through the relay - the maintenance switch is no longer in circuit.  The BG wire is actually the feed from the other end of this internal relay.
 
It gets complicated on the UK car by the dip/dim circuit.  This adds an additional relay in series with the light switch (in the same pattern - kind of like cascaded).  This relay gets it\'s control signal for the coil from the dip/dim module which operates both the new up/down relay and another relay that switches a power resistor into the dipped headlights wire.  With the engine on and sidelights selected the lights are supposed to pop up and will be dimmer than normal.
 
You can make the lights behave like the US models by unplugging the dip/dim relay module behind the glove box.

[grinder]

how long did it take you to solve before wanting to burn it... err hi mr insurance, it must have been an electrical fault that caused the fire:flamed
richard

ha ha ha took me a good few nights to sort it out

at one point i ended up with a load of wire wedged into the battery and into the back of the switch / relays

got it working ( aswell as using the power probe ) and then just hard wired them correctly

[richrx]

if you disconnect the pop up lights relay, and the headlights relay, should the lights still pop up via the swith in the cabbin?

[Prof]

Not if you unplug the pop up relay - the lights relay isn\'t needed to make them popup, but disconnecting the pop up relay breaks the circuit for the switch.

[richrx]

Not if you unplug the pop up relay - the lights relay isn\'t needed to make them popup, but disconnecting the pop up relay breaks the circuit for the switch.

ok, thats happened twice now :3Confused

still proding away at the moment, checking wires etc.


richard

[Prof]

ok, thats happened twice now :3Confused
 
still proding away at the moment, checking wires etc.
 
 
richard

Just had another look at the circuit - looks like they can go up, it\'s the down control that\'s interrupted by the external relay - that\'s if the circuit is to be believed ! lol
 
If you unplug the relay can you put the lights down if they are up?

[richrx]

the pop up mechanism works perfectly if i take out the 4 pin headlight relay, so im thinking the problems here!

i think im almost at the bottom of it



richard

[grinder]

is the relay working OK - you can test with some wires and battery and you should beable to hear it "click over" and then "click back"

i have a RAFT of relays in the garage - so if you can prove its at fault i can send you one

[richrx]

im just about to head out and look at her again. i dont think it is working, theres no click when i put power to it

is it the two coil plugs that need powered to get a click noise?


richard

[Prof]

im just about to head out and look at her again. i dont think it is working, theres no click when i put power to it
 
is it the two coil plugs that need powered to get a click noise?
 
 
richard

Yep - and when you do it, just don\'t be holding both terminals at the same time :Nono!

[richrx]

right im quite excited!

i got them working...kind of, but i think i know the cause..

1. connect 12v to the red wire at the switch and the pop up lights work, but the headlights still wont go on.

2. connect an earth to the white/green wire at the 4 pin relay, the relay clicks the lights go on, and the pop up lights still work. but obviously the lights dont go off.

so im assuming ive got a knackered switch, which isnt grounding the wire as it should?

please say im right


richard.