Lights

[madmodder]

Originally Posted by JSeaman

I couldn't test the switch until I had traced the wire back through the loom, otherwise you don't know which one to test. The contacts are great, there's nothing to go high resistance - it isn't wires in the switch, it is sprung metal. And if it was the relays then putting 12V into the switch wouldn't cure it.

As for 40s - I read it was 1999 that the CEM was introduced. From my dabbling with the lights I found the sidelights and headlights are independent so to lose both you are probably looking at the switch which is common to them both.

I presume you've checked the bulbs? If you take a piece of wire and run it straight from the battery to the light you should be able to make sure it lights up

The wiring loom under the rad would be worth a look too.

Are you familiar with a voltmeter? You can check for grounding issues with this and start working through the system

you can test the switch with out knowing the out puts you just need to use logic, with the switch in position 1 logic says that only the side lights would be on, this includes front and rear side lights, side markers, rear number plate light and dash light. so although you would not know exactly which was what you would know that those lives would be side light related, then you move the switch to position 2 and test the remainng lines. to pin point it down you could apply 12v to the pins in the socket on the back on the switch and if the relays are good and wiring is good then the function that the wires is connected to would work / light up. a far more simply switch to get your head around if you think im being is illogical is the ignition. you know from the ignition switch you have off, accesory (position 1), ignition ( position 2) and start (momentary position 3) so logic states that there is a minimum of 3 wires from the switch, logic all states that a circut must need power so there would be a +12v aswell. so to find out the wiring combination you test all 4 pins for +12v power with the switch off, this would be the +12v in, then you turn the switch to position 1, and then out of the remaining 3 test for a +12v once located this is you switched ignition live. and so on and so forth.

[JSeaman]

Obviously you don't know my background but I'm quite capable of fault finding this sort of thing but to try and fault find blindly on an issue like this is not practical (in my view, I value my time too much!). what you actually end up with is various wires with voltage on in various different positions and the missing one may or may not be present (in my car I would have seen a number of voltages appear but not the one I needed as it happened).

Anyway, not wanting to get embroiled in a pointless debate - thanks for trying to help

[madmodder]

Originally Posted by JSeaman

Obviously you don't know my background but I'm quite capable of fault finding this sort of thing but to try and fault find blindly on an issue like this is not practical (in my view, I value my time too much!). what you actually end up with is various wires with voltage on in various different positions and the missing one may or may not be present (in my car I would have seen a number of voltages appear but not the one I needed as it happened).

Anyway, not wanting to get embroiled in a pointless debate - thanks for trying to help

as im trying to point out, if you got all wires live as they should be you can rule out the switch and move to somewhere else knowing the switch is putting out the voltage needed to power the circuit, there is obviously a problem somewhere in your system, bypassing it by splicing in a 12v supply further up the chain is not a cure, if for instance a wire is grounded under the dash and blown a relay or fuse due to the short, by powering the system from another point your putting power straight back down that line, a car battery is capable of putting out well over 1000 amps, it only takes around 150 amps on a dead short to set a car on fire, im by no means saying your not capable, im just saying there is a logical way to diaganoise this type of fault and by what you are posting sounds like your going around in circles and missing the problem, being a european car it is wired to din iso spec so the colour of wire used at the rear tail light bulb holder, should be the same colour wire on the switch. if you want to know what wire is what on the back of the switch then once you have figured out the lives from the negs you can bus power straight into the plug and this will let you know what that circuit does.

[JSeaman]

"splicing in a 12v supply further up the chain is not a cure"
I beg to differ

Whilst the battery may be capable of delivering high current, the wire is not. Neither is the fuse in line with that wire so if it were a dead short it would do nothing.

Not going around in circles at all, I got as far back as I needed to implement a fix. I could start ripping out the fuse box, dash and loom to find out where my 12V break is if I wanted a day or two of fun and games but I don't.

[madmodder]

Originally Posted by JSeaman

"splicing in a 12v supply further up the chain is not a cure"
I beg to differ

Whilst the battery may be capable of delivering high current, the wire is not. Neither is the fuse in line with that wire so if it were a dead short it would do nothing.

Not going around in circles at all, I got as far back as I needed to implement a fix. I could start ripping out the fuse box, dash and loom to find out where my 12V break is if I wanted a day or two of fun and games but I don't.

so the new tap has a fuse on it inline before the splice? also its not a cure its a tempory fix, a cure would be fixing the item that caused the initial problem in the first place. thats like going to the doctors with a broken leg and them just giving you pain killers and a plaster. it would not be a day or 2 of fun and games, it should take 3-4hrs to find and cure the fault. it would take about an hour to test all the compenents and about an hour and a half to trace all the wiring through the car. but its your choice, im only giving you my knowledge to help you find and fix your problem. endlessy probing around on a circuit in the right area to find a fault is called fault finding and diagnostics. i will tell you a little story, my brother in a fully qualified mechanic, his new car broke down a few months ago and he tried everything he can think off to get it started again, he could not figure out why it would not start. He rings me up to come out and give him a toe home. once at home he gets out all the tools you can think of and starts running through the car doing diagnostics and checking everything and could not find a problem. He asked for my help first thing i said was does it have fuel in it, he said yes its got just under 1/4 of a tank left, i said well lets rule out the possibility of an empty tank took him to get some fuel and low and behold the car started. a bad connection caused excess resistance on the fuel sender circuit so the car was showing more fuel than it had in it. Moral of this story doesn't matter how good or qualified someone is always start with basics.

[JSeaman]

I think this conversation has gone past useful now. Again, thanks for the input but we'll leave it there