headlight problems

[richrx]

hey again,

ive still not had a chance to look at the idle problem in my other thread, however the headlights have stopped working, meaning i cannot drive the rex at night unless there are street lights present.

ok heres what ive got...
1. side lights work no problems.
2. when i try and flick onto headlights nothing happens.
3. when i try to put the pop up light into the up position using the maintenance knob, nothing happens
4. if i try to flash the main beam, nothing happens.
5. everything else works fine.

what ive done so far...

1. powered the lights using a 12v feed from the relays beside the radiator. all works ok from here.
2. pulled the dash apart and could find only 9v at the live feed for the headlights switch.
3.put a temp 12v feed onto the headlight switch.

now the following happens

1. sidelights work no probs.
2. when i try and flick onto headlights nothing happens.
3. when i try to put the pop up light into the up position using the maintenance knob, they pop up with no lights as they should, regardless of the headlight switch position.
4. when the lights are popped up, the main beam will flash and turn on constant as normal. when i do this the headlights turn on and i can alternate between headlight and main beam as normal.
5. the headlight switch still does nothing.
6 everything else works fine..

im going to double check the power to the indicator cluster just now.

i tried to make it as clear as possible! im confused now :s maybe the switch also? any ideas?


thanks

Richard

[Prof]

FC lights - you\'ve got to love them !
 
I\'ve had just about all the problems with the lights !
 
Most of the problems stem from the fact that the +ve feed from the battery via the 30A fuse is split several times to feed the relays and the switch in the car.  These splits or joins are made inside the harness that runs in front of the radiator - and get\'s damp and salt in it from years of bad british weather - this leads to corrosion of the joins and bad contacts.
 
I ended up running a 12V from the battery to a 1-4 way audio block power distributor - then I took a feed from that to the switch, another feed to the HID\'s I fitted, 1 feed for the fog lights I fitted an the remaining feed went to the 12V wire that feeds the relays at the front of the car.  I think the 12V feed was Red/Green from memory - but you can wire in parallel to any of the exisiting 12V feeds.
 
It can take ages to properly troubleshoot where the 12v is failing - you need a lot of patience - a multimeter, and then set about testing the 12V feeds to all the relays, the switch and so on.  If you use the multimeter on resistance, and take out the 2 30A fueses for the lights (retractor and lights) you are looking for any tests where the resistance is higher than 1 or 2 ohms.  These will indicate a failing connection - I had over 30 ohms on one of my connections - that\'s not even enough to power the relays with side lights on.
 
Symptoms I had are:
 

• Retractor wouldn\'t work - or would close the lights again when the headlights were switched on.
• Washer would only work if the headlights were off - so had to use the maintenance switch and wash the lights with them off.
• Relays would \'buzz\'
• Lights would go dim or off at odd times

[m1tch]

Maybe if you get just the headlights working, you could take the retractor fuse out and manually wind the lights up, it wouldn\'t be ideal, but at least you could drive in the dark until its sorted!

[richrx]

i think its just going to be loads of farting about to sort this.

i just put power through the lights at the relay, and measured the voltage in each socket at the switch end(inside the car), but i have no idea what ones should give a 12v reading. if i had a diagram then i could figure it out. but when i powered the headlights there was 5 or 6 reading 12v and one reading 5v.

11 00 00(plastic)10-xx-xx
00-04-00-00-10-00-11-11

xx- empty and the number relates to the voltage.

no idea what any of this means, maybe someone else will :s


thanks

Richard

[captainbizzaro]

I know this won\'t be much of a consolation but even if you have 12v at a certain point which would insinuate whatever you are testing should work-it still might not if you have a high resistance return so like Prof said all you can do is plug at it with a multimeter. I\'m a sparky myself but auto electrics baffle me like the best of them so good luck!!

[richrx]

ok i thought about that post, and to put it simply, what wires do i need to sent power along from the dashboard to get the headlights to turn on?

its a uk series 5
this is the connecter plug
xx- blank space
00-wire connected

00-00-00(plastic)00-xx-xx
00-00-00-00-00-00-00-00

thanks

Richard

[Prof]

This is the connector pin out for light switch on UK car (by colour):
 
*  RG RW gap gap RY RL WG
 
BR BL  B   R    LO  RB BG RG
 
Colours:
 
RG - Red/Green - Illumination lamps (on dimmer)
RW - Red/White  Hi/Lo Beam switch (ground via a diode when on)
RY - Red/Yellow  - Down Retractor signal
RL - Red/Blue - Up Retractor Signal
WG - White/Green  (12V from battery via 15A fuse - for side lights)
BR - Black/Red  ??
BL - Black/Blue ??
B - Black  - Ground
R - Red  (12V from Battery via 30A fuse)
LO - Blue/Orange - washer motor 12V when pressed
RB - Red/Black - Sidelights
BG - Black/Green - Fog Light Relay - Dip/Dim Relay (behind glove box)
 
 
The wiring diagram is very confused - and gives 2 different connection layouts for the same switch !?
 
Anyway - if you have a long enough multimeter lead - measure between the battery positive or the lights fuse and the Red 12V on the back of the switch - you should see very low resistance (less than 1 ohm) - more than that and you might have problems.
 
Then switch your multimeter back to voltage reading, connect the black probe to a known good earth and use the red probe to measure voltages on the connector :
 
Then you can check the retractor system.  With 12V on the switch - you should be able to see 12V on either the Red/Yellow or Red/Blue retractor control wires depending on the manual switch position.
 
You can test the washer switch - look for 12V on the Blue/Orange wire when you press the button.
 
Finally, with headlights selected on the switch - both the Black/Green and Red/White wires will be showing nearly 0 volts (they are grounded via diodes within the switch).  They will normally read 12V or there abouts when lights are off or set to sidelights.
 
Hope that\'s not too complicated

[grinder]

he he he i had exactly the same probs !!

i have a write up somewhere about how i fixed mine ( with a smiliar pin layout to yours )

let me see if i can find it

oh yeah another toy to invest in - buy a power probe off ebay .. makes jobs like this sooo much easier !

[grinder]

ah i see you found my thread ! LOL

http://mazdarotaryclub.com/forums/showthread.php?t=32221

and in the end i think i ran 2 new wires - one to the switch plug in the car and one to a relay at the front of the car

[richrx]

The wiring diagram is very confused - and gives 2 different connection layouts for the same switch !?
 
:

i think mine will be the other layout, the top two spaces on the right are both blank on mine :s

im off to give it a go, fingers crossed i can get a result!:2Confused

richard

[richrx]

im assuming on the headlight relay there should be a 12v reading from both the coil feeds? only one is producing any power!


richard

[Prof]

Rich,
 
neither layout appeared to match yours - is it a UK car?
 
As for the relay - if you\'ve got 12v one side of it - then a multimeter should show 12v the other side if it\'s not energised, close to 0v if it is.
 
And Grinder is right - powerprobe is an awesome bit of test kit - visual/audio indication of 12v and ground, you can inject 12v or ground into anything - great for energising relays, lights etc.

[richrx]

Its elford tims old car, as far as i know its a uk series 5 convertible. im going to get the switches from PDTAYLOR and try them. i got the pop up lights to work via the maintenance swtch by adding a 12v feed to the switch, but i suspect the switch may be knackered.

also in my mucking about managed to get smoke comming from the indicator stalk... the indicators work ok, but the lights dont flash now... so i think i knackered that! all in all no worse than i was before really! cant do much till i get a new switch.


richard

[grinder]

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

[richrx]

:xconfused

This is the connector pin out for light switch on UK car (by colour):
 
*  RG RW gap gap RY RL WG
 
BR BL  B   R    LO  RB BG RG
 
Colours:
 
RG - Red/Green - Illumination lamps (on dimmer)
RW - Red/White  Hi/Lo Beam switch (ground via a diode when on)
RY - Red/Yellow  - Down Retractor signal
RL - Red/Blue - Up Retractor Signal
WG - White/Green  (12V from battery via 15A fuse - for side lights)
BR - Black/Red  ??
BL - Black/Blue ??
B - Black  - Ground
R - Red  (12V from Battery via 30A fuse)
LO - Blue/Orange - washer motor 12V when pressed
RB - Red/Black - Sidelights
BG - Black/Green - Fog Light Relay - Dip/Dim Relay (behind glove box)

OK back on track, this is the layout of my plug, similar, but in a kind of reverse order?

WG - RL - RY(PLASTIC)RW - XX - XX
RG - BG - RB - LO - R - B - BL - BR

 

Anyway - if you have a long enough multimeter lead - measure between the battery positive or the lights fuse and the Red 12V on the back of the switch - you should see very low resistance (less than 1 ohm) - more than that and you might have problems.)

i read 30ohm on this wire. so this needs a rewire! one problem solved. :Party

where do the other cables draw their power?
 

Then switch your multimeter back to voltage reading, connect the black probe to a known good earth and use the red probe to measure voltages on the connector

WG - RW - RED  - BL - BR all have around 9-11.5 volts going to them with no switch. BG reads 4 volts.
 

Then you can check the retractor system.  With 12V on the switch - you should be able to see 12V on either the Red/Yellow or Red/Blue retractor control wires depending on the manual switch position.

this works perfectly with the maintenance switch. but not with the headlight switch with the new 12v feed. could it be the switch? or wireds burnt out in the loom?
 

Finally, with headlights selected on the switch - both the Black/Green and Red/White wires will be showing nearly 0 volts (they are grounded via diodes within the switch).  They will normally read 12V or there abouts when lights are off or set to sidelights.
 
Hope that\'s not too complicated

i\'ll check next, the battery died :2Rolleyes

 
thanks for keeping with me!!

richard