Headlights dont work :(

[Prof]

BA is where the power should be coming from - it should power the relay that drives RU / RD, and also feeds the pop up switch which always overides the relay - switch is up - lights up (but not on) - switch down - lights obey relay (lights on - lights up  / Lights off - lights down).
 
So the switch itself should be tested - if feeding 12V to BA and operating the switch doesn\'t raise the lights, then the  switch or pcb tracks are fried.  If you had a short in the wiring loom at some point - or one of the motors was jammed and caused a heavy load on the circuit, it could have burnt out the pcb track - and if you tested with other switches these may have gone as well.
 
Assuming you can get the switch to work, then the next likely thing to have failed is the relay in the switch - these relays are a little bit ****ty - the ones in the wiper switch are notorious for failing - Farnell or RS do an exact OMRON replacement part - which is far superior - I had to do this on my wiper switch, but also had to repair the actual rotating switch part and the pcb as both of these got fried by a short in the loom

[grinder]

thanks prof

i will have another look tonight and see whats going on

so if im getting 12v to BA and 0v to rd/ru when the light switch is operated - then we can guess that i have a lot of broken switches ??

i had a look at the inside of a switch and it seems OK to be honest

unless the probs lie with it being a jap car and i have no idea what switches im using !! LOL

Stu

[grinder]

hiya chaps me again

right then BA is only seeing about 5v - so this is a problem

i stuck the power probe in the back with a light switch attached and got the lights to pop up and down on the switch - so partial success

now more probs have arose

1 - i can still get side lights and the lights stay down ( as they should )
2 - next click on the switch - lights pop up
3 - but no lights come on
4 - no dip , no full beam
5 - indicators have stopped working aswell - but by powering the connector they do work

so do i need the indicator switch to work to determine if its dip beam or full beam

and they worked yesterday so why not today

managed to blow the illum fuse - so changed that aswell - but the indicator one seems fine

and i even got the maintenance switch to work

so now i need to do ..

1 - get 12v to the main switch - not sure how though
2 - get the indicators to work
3 - get dip / full beam to work

the head fuse is only seeing about 8v and thats dropping to just over 5v at the cluster - any ideas why ??

come on chaps - im nearly there

Stu

[Prof]

Yep - I can help you there.
 
The 12V feed to the switch comes off the 30A lights fuse, and then enters that crappy loom that runs in front of the radiator.  It has joins in it, and gets all the weather God throws at it - so you get corrosion and poor joints.
 
Basically your wiring loom has faults in it - there are 2 solutions :
 
1) Get the bumper off or crawl underneath and try and find the bad connection and repair it
 
or
 
2) Run a new 12V feed from the fuse to the switch - or intercept the wiring loom on the drivers side near the Pressure sensor and cut the original 12V wire and stick your new one in place.  Recommend solder joints with heatshrink on if you can.  You may also want to consider feeding the same 12V wire to the relays to keep them happy as well.

[grinder]

not exactly what i wanted to hear - but its a start

but the fuse is only seeing 8v - and thats only about 6 inch from the battery - so could the probs be at that end

im assuming that i can check the resistance of the wires once i match the colours and such like and try and trace it around

will it be a bad connector - or just wire thats bad ?

just out of interest .. how do the wires run

battery  -> 30amp fuse -> cluster -> switch

or something else

just so i know where to get for voltages and where it seems to be dropping

stu
( sooo close i can smell success )

[Prof]

Stu,

When I followed the routing on mine, the feed from the fuse joins the wiring harness with the headlamp washer, and then passes down in front of the radiator and oil cooler.  There are a number of spurs off this to the lights, relays and so on, but this whole harness then passes around the drivers side and along by the strut tower and through the bulkhead to a large connector - from there it passes to the cluster switches.  The joins are in the 12V feed and are inside that harness that is attached to the pipe that runs in front of the oil cooler - I think it has something to do with the power steering system - the pipe that is.

By \'wiggling\' the bulges in this I was able to get better/worse connectivity - and I have seen one of these harnesses stripped bare as well - but I can\'t remember what type of connections are used.  It may have been crimped or soldered - but that was 16 years ago, and weather takes it\'s toll on this.

Try the flying wire - it worked for me - got me through the MOT - I will strip it completley and replace this coming year - but the hot wire works well for now.

[grinder]

i will have a look tonight and see if i can see some bulges

and what flying wire are you on about ??

running a 12v feed to the back of the switch

i must admit - im not sure where to start

Fuse
Battery
Switch
Harness
Bulkhead connector

the fact that i only see 8v at the fuse means it must be bad around that area somewhere ??

i have looked at the harness and can say that they are still covered up and NO exposed wires

Stu

[Prof]

Flying wire - I put a wire in between 30A fuse (after the fuse - as battery to fuse was ok) to the lights relay, as that was where the fault was on my loom.  I had over 30 Ohms resistance between fuse and the relay - it should be fractions of an ohm.

The symptom was that I could operate the headlight motors, but as soon as I turned on more than sidelights, the lights would drop and the relay\'s buzzed.  By disconnecting the lights themselves I could get the motors to work and get the relays to hold, but as soon as the load from even 1 light was present there was insufficient voltage to hold them on.

You could make the same measurements as I did :

Resistance between battery positive and hot side of the 30A fuse, resistance between cold side of fuse and lights relay red/green wire (not the lo/hi beam - the other one that feeds it) and the resistance between BA on switch and the relay - can\'t remember wire colour

I had good low resistance between the switch and relay - so wiring loom was good here, bad resistance between relay and fuse, good between fuse and battery.  So I needed to jumper a wire between fuse and relay - I used heavy gauge multistrand copper wire - capable of 25A - the lights on full beam take 10A !!

If you want - take the readings and let me know what values you get.  Don\'t forget - unplug the switch, relays and fuse - you don\'t want any part of the circuit having 12V on it and cocking up the readings !

[grinder]

good man dave

makes much more sense now

just need more hands to test from inside the car to the outside with a meter

i like you error checking theories though - makes sense now

and i can bell it thru aswell to see what wire goes where - and then check it for resistance - im praying that its not a massive piece thats faulty

and idea on why the lights come up but dont come on ??

do i need a set of working switches ( headlights and indicators ? )

Stu

[Kron]

good man dave

and idea on why the lights come up but dont come on ??

Have you checked the actual bulbs yet?

Edit- scrap that, Just read the first page. Always late.

[grinder]

Kron -  see the first post

[Grizzly]

Stu, I\'ve found the Light switch (hence the delay) Where exactly am i looking for the code?

The only thing i can see is on the Clear\'ish Plug part of the Switch, That says W01, I know it was Working fine when it came off the car.

I have also found a Indicator switch if thats any Use to you. (That only has 513319 stamped in the back of it??)

If you want them PM me your Address and i\'ll send them over to you.

[grinder]

cheers chris

can you keep hold of them for a day or so - i MIGHT have figured it out - just need to check a few final things

W01 - so thats not the same as my codes either - any idea if they are UK spec or JAP/US etc..

Stu

[Grizzly]

Urm i\'m not sure but i would guess its a UK one becouse i\'ve only ever owned 1 Jap T2 and i\'m 80% sure it did\'nt come off that.

Yeh no problem, The only reason they came out was to see if they where any use so they don\'t have any Purpose lined up.

[grinder]

need to check the wiring as of Profs post - and then work out what i need

thanks again for the offer though - if you make it to the dec meet - i could collect then ?