Hazard Switch & Indicators - fault diagnosis

[Mo Murphy]

I suspect you're going to have to start pulling the dash apart to track it down alas.

Mo

[ZIKOMO]

Problem solved: It was the telltale in the instrument panel.  

My car has one light covering both indicators so I'm guessing this has a couple of diodes that should block any cross feed.  Whatever the device it must have failed and that allowed it bridge both directions.  Taking the wires out from the plug was a major so as a temporary fix I've just cut the feeds and will solder them back when I get a new binnacle cluster.

Tracking this down was a real challenge for me so I hope some other unfortunate might benefit from sharing.

Cheers, Alan

[Mo Murphy]

Well found Sir !

[western]

17 hours ago, ZIKOMO said:

Problem solved: It was the telltale in the instrument panel.  

My car has one light covering both indicators so I'm guessing this has a couple of diodes that should block any cross feed.  Whatever the device it must have failed and that allowed it bridge both directions.  Taking the wires out from the plug was a major so as a temporary fix I've just cut the feeds and will solder them back when I get a new binnacle cluster.

Tracking this down was a real challenge for me so I hope some other unfortunate might benefit from sharing.

Cheers, Alan

on pre td5 vehicles with 1 indicator light on the dash, it is connected to left & right circuits, so when indicating left [live side] the opposite wiring becomes the earth [ground] path so the bulb flashes as expected & does the same when right indication is used, no doides in the indicators system, on Td5 defenders onwards there are seperate lights [led on td5] for left & right indicator circuits.

 

the above single dash light causes problems when owners fit led indicators to the vehicle, as the led use a lot less current to function & the amp draw doesn't work the dash light correctly. 

[xxxnumbnutzxxx]

hello, im having an issue with my 89 Ninety and was hoping someone could help me solve it

my hazards and indicators have been a bit spotty since i bought my landrover a year ago but they completely stopped working on Saturday, after a few checks i thought it may be the flasher relay so ive replaced it with a new one, only its not fixed the issue

following the checks on here all fuses are ok,  im getting 12v to the purple permanent at the back of the connector and i have two different hazard switches that both worked in the past but arent now when connected 

on the first two tests from the purple permanent to either indicator im getting nothing, from the permanent to the flasher supply using the indicator stalk with ignition on again nothing happens 

for the second set of tests the light switch supply to either indicator the correct side lights up, then for the switch supply to the to the flasher supply using the indicator stalk each side flashes fine from the stalk 

 

so from this i gather the new relay works, the indicator stalk works, the wiring to the lights works the issue must be with the purple permanent but i cannot think of fix and im hoping someone here can shed some light on it please

 

[pete3000]

so if you have measured the 12v purple feed to 0v and theres nothing, it's worth checking the fuse first then tracing the wire until you get 12v. the purple is permanent live (there with ign key out), also powered should be horn, clock, sidelights, interior lamp/s, trailer socket, and the hazard circuit. There should be an associated fuse for the clock, horn and interior light.

Do your indicators light if you put 12v from eg brown wire such as cig lighter?

 

Pete

[pete3000]

ps also post your location up, which may help.

[Roverdrive]

 Morning I am in need of your collective wisdom!

i have no power supply to the hazard light switch on the purple and brown wire. The interior lights don’t work either. The fuses are all good, and I have checked for 12v on the back of the fuse box. According to the diagram I have,  this is fed from fuse no1. But this is shown as a purple wire, not purple and brown. Does anyone know where the header is by any chance?

 

[Roverdrive]

Sorry should have added td5 90. 2001 model year I think, but it is ex military

[Roverdrive]

Scratch that, I am obviously having a blonde moment. I had he 300tdi wiring diagram not the Td5. Who knew there was another fuse box? Oops. 😬 

[xxxnumbnutzxxx]

10 hours ago, pete3000 said:

so if you have measured the 12v purple feed to 0v and theres nothing, it's worth checking the fuse first then tracing the wire until you get 12v. the purple is permanent live (there with ign key out), also powered should be horn, clock, sidelights, interior lamp/s, trailer socket, and the hazard circuit. There should be an associated fuse for the clock, horn and interior light.

Do your indicators light if you put 12v from eg brown wire such as cig lighter?

 

Pete

thanks for the reply 

solved the feed issue,fuse was fine, the cable was undamaged but just would not supply a voltage but connecting it to the other purple feed it shares a fuse with works fine

ran all the tests again and everything worked as it should, put the switch in drivers side works fine passengers side - the side repeater didnt light up or flash ripped the wheel arch extension off to get to the wiring everything looked fine but luckily i had spare new repeater as i was planning to change it after a quick swap for 30 glorious seconds everything worked as it should 

i pushed the wiring back into the back into the wing, checked it of the switch again and the 15A fuse blew, put a 20A in worked for a few seconds and blew, tried a 25A just to see what happens and all the lights flashes very dull for a few seconds then stopped and the fuse got warm 

any help on what this means and what to try next would be greatly appreciated 

cheers 

[Roverdrive]

I remember someone coming up with a plan to find short circuits. Make up a test lead with a lamp and two male spade connectors. Put the connectors in the terminals where the suspect fuse should be. If the lamp lights brightly there is a short, and you can start wiggling wires to find it. Bulb should go out when you have found the fault.

[pete3000]

you have a short in your wiring, don't put high rating fuses into the wiring as the next problem will be the good portion of wiring melting out. if you put the correct rating fuse or bulb as roverdrive says, in. then leave the hazard switch disconnected and measure the voltage.

 

If the drivers side works ok, i'd concentrate on the passenger side indcator wiring, can't remember if its green/red or green/white. take the bulbs out of the holders and measure the voltage to black or chassis. looking for my money would be on a trapped or chafed wire where the wheelarch has been disturbed or where the wiring runs out of the chassis/rear crossmember.

To break it into manageable chunks you can unplug the rear crossmember/trailer wiring by the brake/clutch reservoir on the multiplug.

[pantherslover]

Can i share that I have just been on this Journey. I took the switch off and checked out against lukes info. It seemed to be ok.
Couldn't seem to get a voltage off the permanent live. Checked the fuse was ok. Then gave the permanent live a 12 volt feed from the fuse panel. That somehow got it to eneregize. 

All of this reinforces my desire to part company with this vehicle. Goes from bad to worse. Getting out before it sinks.

 

[western]

On 3/30/2017 at 1:04 AM, ZIKOMO said:

Problem solved: It was the telltale in the instrument panel.  

My car has one light covering both indicators so I'm guessing this has a couple of diodes that should block any cross feed.  Whatever the device it must have failed and that allowed it bridge both directions.  Taking the wires out from the plug was a major so as a temporary fix I've just cut the feeds and will solder them back when I get a new binnacle cluster.

Tracking this down was a real challenge for me so I hope some other unfortunate might benefit from sharing.

Cheers, Alan

The single indicator light in the dash provides a earth path via one of its terminals when one of the indicators is selected

so if indcating left the other side provides the earth route

[Ex Member]

You do know you answered a question from 1.5 years ago....

[western]

Was actually replying to pantherslover post, don't know why I quoted the older post.

[Ex Member]

Your advice matched the quoted post.  I've no clue what pantherslover is complaining about.

[western]

Don't know, I must of had brain fade this morning, 

[Vedat VURAL]

On 4/12/2008 at 11:53 PM, LandyManLuke said:

I wrote this for another forum, I thought it might be useful here too.

The hazard switch and indicators often cause problems in defenders, most commonly the indicators stop working, but the fault is actually with the hazard light switch.

This post aims to explain how the hazard switch works, why it's malfunction stops the indicators working, and how to test for and diagnose the fault.

To get to the back of the hazard switch, remove the two screws and pull the switch panel out. you'll then see this.

The multi plug has 7 wires going into it, there's also the Black (red trace) and Black wires, which are connected directly to the switch body. these are for the indicator in the switch itself.

Black(red) - indicator supply

Black - earth

Remove the multiplug, you will then see the two sets of pins, x3 and x4, top and bottom (as viewed in the photo, not as mounted in the dash).

The top set are concerned with powering the flasher unit, the bottom set dictate what the flasher unit actually lights.

This picture shows the 4 wires that connect to the bottom set of pins

And this picture shows the 3 wires that connect to the top

To make things easier to see, here is a schematic of the switch.

With the Hazard switch in the 'off' position

'Suppy to flasher' is connected to 'Light switch supply' - which comes on with the second click of the ignition switch

With the Hazard switch in the 'on' position

'Suppy to flasher' is connected to 'Permanent Supply' - 12vDC

*Flash* is connected to 'Left Indicators', 'Right Indicators', and the 'Switch tell-tale'

What this means is, if the switch is faulty, the flasher unit doesn't get a power supply, so it can't flash the indicators via the indicator switch on the column.

You can test the switch using a multimeter (continuity or resistance), or test lamp. You can also test the vehicle wiring as follows.

You will need a fused piece of wire (or test lamp), you don't want to risk a dead short if you get it wrong.

This is what i made to test the wiring, the lowest value fuse i had was 5A.

If you link 'permanent supply' (purple) to 'Left indicators' or 'Right indicators' the indicators on that side should light, constantly though, not flashing. this proves the bulb wiring is ok and you have supply to the loom plug.

If you link 'permanent supply' (purple) to 'supply to flasher' (light geen), the indicator stalk switch should work the indicators as normal (flashing). The indicator switch is connecting *flash* to 'Left Indicator' or 'Right Indicator' - the wiring is duplicated at the stalk switch. If you want to make a seperate link wire you can replicate the stalk switch action at the loom plug as well.

You can repeat the two tests above, using 'Light switch supply' instead of 'permanent supply', the ignition switch will need to be on the second click.

'Switch tell-tale' is the live supply to the bulb in the switch housing, it is grounded by the seperate black wire connected to the switch body.

Dear Luke,

I had exactly the same problem with my old land rover.   It drove me mad when all the indicators stopped working after switched the hazard lights on.  It never come back to normal when I switched it off.   I had such a relief when I come cross your article. First I realized that I wasn't the only one, secondly I solved the problem with your help.

I just wanted to THANK YOU for your problem-solving article about hazard switch faults.

Vedat from Turkey

[Greg Tate]

My Defender is a 1992 model 110.  Of course the hazard and blinkers don't work.  I've replaced the relay, the hazard switch and confirmed all my fuses. I've confirmed no shorts or poor connections.  When I engage the blinkers, the dashboard shows a steady light.  Both blinker lights will light one at time if I push/pull the blinker lever manually.  Everything seems to be in place for the hazard and blinkers to work, but they don't.  Could it be a bad blinker bulb (even though both lights seem to work)?

Would anyone like to take a whack at diagnosing the problem?  I'd be very appreciative .  I don't know what else to check. 

many thanks.

[Ex Member]

You need to get the wiring diagram and check for the fault.  I would probably first look at the ground for the flasher relay.

[leet]

Hi Guys, finding this thread very useful. My indicators have stopped working out the blue. Bought new hazard switch and indicator stalk. Found this thread and everything checks out apart from I do not have any voltage at light switch supply. Where is this fed from? 

96 300tdi

Edited September 20, 2019 by leet

[Chambo110]

Been through all replies but can’t find my issue..and it’s driving me mad 

before I start with Luke’s cracking write up  would anyone like a stab in the dark..

1987 110csw

Hazards work fine .. indicator L or R won’t work on first attempt, if I cancel it out and straight away “re indicate” 9 timed out of 10 it will work

this is my 2nd stalk now

any quick suggestions or brainwaves ??

 

 Thanks 

[Snagger]

I’d try a new flasher unit.  But check all the terminals in the system are clean - they corrode with age and that creates electrical resistance.  Submerging the terminals in coke will remove the corrosion and dirt over a few hours and a glob of grease will keep them clean when you put them back together.