MY door light switch & wires ???

[steptoe]

Doing my head in.

I have gone to the source - back of switch below the Brumby seat belt. Using one of those sometimes too clever for me type power test lamps. Test light uses pos and neg power off battery, gives mid light to both green and red LEDs, touch pos power, green goes out, red lights up fully. Touch probe to earth and green goes full bright, red goes out.

Should not be hard - two wires come out of loom - discnnected from switch, one has bright red (power you would think) , the other bright green (earth)

connect them to door switch, let switch pop out as if door is open, earth wire stays earth, but power wire reads full green ??

My intention was to tap powwer so I can add some foot well courtesy lighting ( or sill plate lighting like the new AMG A45 - see where $96k goes ! )

Just thinking that fancy test light might have me tricked and need to just hook up courtesy lights and see if they light up how I want .

The fancy test light might be getting an earth from other side of light bulb in roof - forgotten how shite the MY Brumby roof light is !

any clues ??

any readers ?

Or fb got 'em hooked ?

[Silverbullet]

Would this be one of those switched earth moments or whatever it is these cars have? Like I remember reading about in the headlight relay mod...

Maybe you have to end up taking a signal from a wire under the dash that controls the warning lights in the instrument cluster (or HUD )

[tambox]

Trap for young players Jonno.
This where you get into readings that dont make sense, using an LED tester, you need to understand current as well for it to make sense.

If you did the test in the dark, you may see the roof light globe light very dimmly, when you have the red LED glowing.
The LED needs a lot less current than the globe, so the globe in effect is a resistor for an LED (after all its a piece of wire).

One side of the globe (acting as a low value resitor) goes to +12, hence the LED lighting up. Take the globe out and it wont.

[Bantum]

Another trap is the 'door ajar' warning light - See wiring diagrams I did for my Brumby :



This first diagram is existing condition - Note : The door switch can only operate the dome light the when its selected correctly on the dome.
The other interesting thing is that the circuit also powers your stop lamp, so its not really suitable for adding more things to it.

This second Diagram shows what I propose to do :



I decided it would be easier to run the 'Puddle Lights' of a relay - Primarily because its much easier to add more on the same new circuit later, without affecting the current draw on the instrument indicators ...

Bonus of they way I've shown is the door light should still operate like normal ( with the dome light in control ) or you can run a separate switch ( via power supply line ) before the relay to make it come on independently ( not shown ) ...

Do Note : You'll need to 'break' the existing circuit ( @ power supply 'LY' Line ) to insert the new relay ...

Cheers, Bantum ...

[FujiFan]

Door/courtesy light circuit uses multiple earth paths, As tambox might be suggesting, ignore the LED test lamp.

As a start:

Remove each pin switch and test off car with DMM for clear break in continuity, ie 0.05 ohms or less with given switch closed - infinite with open state. If all good then clean each self tapped threaded hole for each switch clear of rust/corrosion - including the screw that ties pin switch to body. high resistance contacts from switch to chassis/body cause problems. From memory stainless screws are used, but even they pick up some rust/ corrosion. every earth point should be spotless. The power provided to courtesey is independent of any + switched part of fused components. also check dome light contacts.

As Bantum suggests, best not to add extra load to stop lamp circuit - this is a primary safety function circuit and should be left untouched, unless you have a hold of it.

J.

[steptoe]

extra load - already done that once before - trailer brake lights or stop lights as they like to call them They are now LED. Also had the tiniest bezel socket type bulb and green lens mounted in steering column covers to light up the key hole. Oh , and also had a plain wedge bulb in a Triumph 2500 boot light mounted in the sports bar.

This is on Brumby 1's replacement. No tow bar or trailer socket as yet. While at the wiring behind the seat belt been soldering into the other green with black trace wire to mounted an inside rear window stop lamp bar LED (an $18 canopy job from ARB)

Only thought as tiredly typing that I should go back to the old one clip, one probe, one light test lamp as LED has tricked before, so too the DMMs diode tester acting as a continuity tester on light bulbs

Brumby 1 also has a relay off the door switch to turn parkers and dash lights on when door opens, but my later mounted on the back of the PCB headlights on screamer goes off as well now. Diode may have a role next attempt.

While I was building in a tacho and oil pressure gauge, noticed I could have saved Fuji a small fortune - they included rear door ajar bulbs in the board !! Must have been a dual cab Brumby on the cards

On B1, I swear I got the extra light power from up near the bonnet release cable pull.

Nice diagrams Bantum , reminded me to add my customary second battery to body earth cable, and maybe if it is the odd earth switching, use both wires at switch to the relay 85 , 86 terminals should work, and maybe a diode protected relay as well for good measure. Just worked out why you call them puddle lights - another comparable water/electrickery term - to go with flood lights

[steptoe]

earth switching ?? I don't think so ... swear a UFO buzzed me yesterday on the highway .... just patched into the working pair of wires off the light switch at door.......

while door is open, relay is not energised, roof light is off

while door is closed relay is energised, roof light is on

no LED test lights were harmed or even used in this demon.stration

Must pull other Brumby down to the wire to resolve when ICBF

wondering if an 87/87a relay will do it ?? Likely not, don't want a relay left energised while not in operation

aha...looking at the old Gregories diagram - the power for the roof light looks to go through the PCB at the rear of dash cluster between door switch and roof light - this must be what I intewrcepted many moons ago on B1. Manual shows all four door switches have a common Black wire and each then has its own individual colour and trace

[steptoe]

bloody Earth switching it is - but not as learned with horn and light switching and use both wires on the relays 85 & 86 terminals to get it to work, nah, just use the non black wire at the back of the switch is green/black trace on front rhs door ? use it to connect as the Earth.

This sort of blow by blow detail should be factbooked eh ?

What I did was to run a wire direct to battery pos, snatch the std old test light aligator clip on the other end, poke probe at this green wire, got what I wanted I think.

So, a relay with battery at both 30 & 86, green wire from door switch to 85 and I should have light pos power to my courtesy foot lights say should, yet to test and confirm - just getting ready for fb twitter format of news

the in dash warning lights only poower up when IGN is on and door ajar, or some other fault

[like] tw

[steptoe]

I'm back again as promised , so soon too, would I make a good facebooker ?

I can confirm , one of the green/black trace wires found on 6/89 make date Brumby at drivers door switch RHD can also be found as the loom scoots up towards the bonnet release handle, under the cover board. You want to find as I did - pos power when door button is in, no power when it is out. Tap into it not cut, but may do same thing for you, dunno - hooked it up to relay pin 85, ran one wire from battery or from batt section back of fuse box to do two pins on relay 30 for power supply and across to 86. Then, you should have pos power to hook up to courtesy lights that then have a ground other side.

No flash diagrams like Bantum until I find out how

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[steptoe]

now, guess just need to find some old loom with a green/black trace wire to keep up the detail in the loom