It just don't make sence!
It just don't make sence!
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Discussion

Oz2

Original Poster:

962 posts

219 months

Sunday 17th April 2011
quotequote all
Interior light!!!!!!!

one light in the centre of the hood (roll bar section) 3 wires.....black,purple/white and purple/red.
SH bible only says black and purple/white no mension of the other one.....
I run a flying wire from the battery + to them, B and P/R light up, same at switch (door) nothing on the P/R this must be the pos but where does it come from coz it aint live! SH says the time clock,Wrong thats blue/red.....Im no sparky but it can't be that hard am i missing something?
1989 350sx (400se body) All the electrics work now apart from this poxy light. I've got a new model Transit interior light to replace the old broken one but I would like it to light up and not just fill a hole.......
HELP!
Thanks

Adam

mike.williams

135 posts

229 months

Sunday 17th April 2011
quotequote all
Adam,
Not at home so no Bible or car...
I take it you mean sparks when you say 'light up'?
I'm sure mine has the facility to work off the open door or just to be switched on..
That, to me, takes three wires.
Do you have a meter? If not, connect a bulb between the wires two at a time and see what happens.
my guess would be one is +12v (from battery) and the other two will be switched earth paths..one from the door switch and one for the switch on the unit? Or one wire from each door switch?
Enjoy! but avoid the 'does it spark' method.. might turn messy one day.. smile
Mike

mike.williams

135 posts

229 months

Sunday 17th April 2011
quotequote all
just a thought, the 12v will be fused, not straight from the battery, have you checked the fuse/fuse board area?
Mike

jmorgan

36,010 posts

315 months

Sunday 17th April 2011
quotequote all
Door switch feeds? Two doors, maybe they are earthed and the other is the batt feed?

Edit. Oops, covered. Mine operate off the door switch abut cannot remember if there are footwell lamps as well.

Wedg1e

27,043 posts

296 months

Sunday 17th April 2011
quotequote all
It's traditional for car interior lights to have a 12v permanent feed but to be earthed by the door switch - which works fine on a steel-bodied car.
My drawing suggests that the earths are permanent and the feeds are switched, so one feed (white/violet in my case) is fed from the door switches and the other (violet) is direct so that you can put the lights on with the doors closed.
If you can't find 12v anywhere, with or without doors open, it does sound like a fusing issue.

Oz2

Original Poster:

962 posts

219 months

Sunday 17th April 2011
quotequote all
Thanks guys,
Yes Im not relying on sparks when i siad light up i ment the tester (screwdriver thing with a wire coming out the handle and a bulb in the handle).i'll have another look tonight and see if i can shine any light on the issuerolleyes

jmorgan

36,010 posts

315 months

Monday 18th April 2011
quotequote all
Ah, yes, memory comes back after many hours driving yesterday (legal limit not breached, just). My light does work off the switch. Had to put a lot of effort into the contacts about a year ago. They were really corroded. Combination of a poor door switch as well. All the voltages and earths were there, they were just not meeting through the right bits. Replaced one door switch, cleaned the other and good clean of the light bits.

Got a diagram of the 400 that someone sent me here.

Link

It is of a 400 but it shows the door switch and hoop light.

mike.williams

135 posts

229 months

Monday 18th April 2011
quotequote all
Yes, that drawing makes sense.. switched earths and power from the RADIO/Clock? biggrin Well shared anyway..
At least that gives you somewhere to go and look for the other end of your none 12v wire. wink
If your clock and radio have power then your search is reduced somewhat..
Mike

Edited by mike.williams on Monday 18th April 07:43

Oz2

Original Poster:

962 posts

219 months

Monday 18th April 2011
quotequote all
I had a look this morning and the radio does have the same colour wire going to it,i'll go out tonight and test it, would it make a difference if the radio is not pluged in? the clock is working and so was the radio until i removed it....

Oz2

Original Poster:

962 posts

219 months

Monday 18th April 2011
quotequote all
red/purple wire at light is dead should be live, I found the red/purple wire at the radio which is live as is the clock, are they the same wire? or if they are jointed where should I look? auto-electrics is'nt my strong point but I've managed to fix all the other stuff and this is only an interior light confused

Thank for your help

Adam

jmorgan

36,010 posts

315 months

Monday 18th April 2011
quotequote all
Can you find where the wire gets to the hoop at the join? Maybe that is its weak point?

Jonny weggie

1,607 posts

222 months

Monday 18th April 2011
quotequote all
Adam try your tester [screwdriver thingy] put it on what you think earth, open your door and touch the other two wires to see if it lights up, then close the door and try the same, hopefully only one should light up.
If not, then good luck.

jonny.

mike.williams

135 posts

229 months

Monday 18th April 2011
quotequote all
jmorgan said:
Can you find where the wire gets to the hoop at the join? Maybe that is its weak point?
This is probably the key. wink
Problem is I don't know where they would have spliced the wires... Remember that the drawing whilst electrically correct, will have no resemblance to the lengths of the wires. It is laid out like the London Underground map.... looks simpler, but everything is not geographically in the right place...so the small length between join and clock may well be as long (or longer) than the run to the radio..
Thinking sensibly, the splice (join) is more likely to be near the fuse (possibly even at the fuseboard..)as the route to the hoop will be along the tunnel or bottom of a door?, not up into the dash..scratchchin
Help and enlightenment needed from someone who has / had the carpets out and seen the routing of the loom. Wedg1e, The Hatter or many others may have that info. The Hatter has posted recent photos of his SEAC resto sans carpets.. maybe that will help?
Splices are the most likely fail point.. even if you have to resort to following the wire back until you locate it, it could well be the quickest route to a fix. smile
You are coming to the end of you testers usefulness in this search. It may well be worth your Ozzy dollar to buy a cheap and cheerful volt/resistance meter... a £10 meter is worth it's weight in gold.. I f you do buy one remember if yo are looking for continuity the meter will not be happy when it finds volts on the line! Battery disconnected is the way forward.. wink

Good luck, Mike

mike.williams

135 posts

229 months

Monday 18th April 2011
quotequote all


Having just looked at The Hatters thread, a photo shows a loom running along floor line under passenger door..
The splice is MOST likely to be before it leaves the footwell on its journey rearward... otherwise they would be running wires forward from the join back to the clock/radio wink
So time to get upside down in the footwell I think..rotate
Mike

Edited by mike.williams on Monday 18th April 15:56

Oz2

Original Poster:

962 posts

219 months

Tuesday 19th April 2011
quotequote all
"It all makes sence!"
This is what first got my attention

then as you know I went searching for a live wire, the problem was this

And the result is

BINGO!
what got me confused was from the fuse, the wire is purple to the plug, then it changes to purple/red to the light, but at the radio and clock it purple/red,oh and the wire runs along the tunnel on mine.

Thanks for all your help once again, this is the best thing, all this info at your fingertips,

Cheers

Adam 350sx(with fully functioning electrics)thumbup

Grady

1,233 posts

291 months

Tuesday 19th April 2011
quotequote all
Say, that's a logical place for a light. My 85 has them in the foot well (not bad) but my 86 has them in the parcel shelf by the speaker - fairly useless.