Hazard lights failed the MOT

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Patman1200

Active Member
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908
Location
RAE Sleepy Valley
My 90's hazard lights don't work, so it failed the MOT obviously. It failed on some other things I don't have the time to fix so I've left it with my mates garage to repair and re-test.

The question is does the hazard warning light bulb in the dash stop the hazards working if it has blown? :confused:

I swapped the switch and relay with the good ones out of my 110 and the wiring looks the same and untouched and they still didn't work.
 
My 90's hazard lights don't work, so it failed the MOT obviously. It failed on some other things I don't have the time to fix so I've left it with my mates garage to repair and re-test.

The question is does the hazard warning light bulb in the dash stop the hazards working if it has blown? :confused:

I swapped the switch and relay with the good ones out of my 110 and the wiring looks the same and untouched and they still didn't work.

The bulb makes no difference other than it needs a tell tale for mot, looks like you have lost the live feed, blown fuse or sumat.

Did you put the 90 bits in the 110 and see if they work.

A word of warning tho when working on electrics like this, specifically when swapping bits, lift the bonnet and slacken the battery terminal. If you make a mistake and something shorts you can never find a spanner to get the battery disconnected and your motor goes up like "poof"
 
the hazard system on landys is very complicated.

If you are SURE the switch you have fitted is good, make sure its connected up right, and check the little connections either side of the switch. You got a wiring diagram for yours?
 
first thing to do is check power supply to switch then trace it from there. if you have power in then power out when switched on then relay and wiring to it is next step.
 
The 110 went through the MOT and passed 1 hour after the 90, so all the switch and relay definitely work. Also the fuses are all ok.
I have several wiring diagrams and the colours of the wires don't match up..... but the layout of the 90's wires are the same as on my 110.

Confused? We were last night when trying to sort it. We also ran an extra ground to the switch and relay and it still didn't work.

Ah well, I'll leave it up to my mate to fix :D
 
I had the same problem! With help from this lot...........turned out to be a bad earth! Find your main earthing points and clean the connections! My earth fault which caused the problem was on the rear door electrics!
 
Hazard light switches are notorious for being faulty/failing.
Mine worked for the mot but after switching the hazards off, the indicators didn't work as they are wired through the haz switch.
Flicking the haz switch on and of a few times sorted the indicators out again.
New switch may sort it out.
 
the hazard system on landys is very complicated.

I am disappointed! Electrical engineering student thinks the circuit is complicated!

Yeah I guess it is, well at first, it is quite simple to work with once you understand how.

Essentially there is the flasher unit, it flashes, thats it, the hazard switch does all the switching to make it all work, without it the whole system fails - so as boydy said, make sure the switch is 100% and connected well.

In normal mode it routes the flashers live out to the stalk where it can then be sent left or right and also keeps the RH and LH circuits separate, when the circuit is made via the stalk it flashes the respective circuit.

When the hazard switch is in hazard mode, it takes the flashers output via the switch (which is has just made live via a constant live [purple]) and connects the left and right hand flasher circuits so that the whole lot flashes together.

I have lying on my desk somewhere the circuit I sketched out which shows the hazard switch exploded (unlike the LR diagram that just shows a MAGIC box)! If I find it I will post it.
 
A diagram would be good - I've kind of worked out what is connected to what, using a multi-meter. My new switch has the same continuity betweeen terminals as the old switch in both positions, so I'm inclined to assume the switch isn't the issue.
Your explanation has helped a lot! I'll check between the hazard switch and the stalk, and the hazard switch and the flasher unit.
 
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