Hazard switch

[Skint George]

Hi guys.

I need some help with a lighting problem with my newly aquired Lightweight Land Rover.

Nothing happens when I turn on the hazard lights except I hear a click noise when I turn it off again. It also stops the indicators working so ther is something happening.There has been some rewire work done by a previous owner so that some wires have been joined to non colour matching wires.

Saying that, the wires to the hazard switch (8 in all I think) haven't been disturbed at the dashboard side.

There is that military Hella TBB20 relay box still in place. Do the lighting wires go through there? As you may have guessed,I know know nothing about auto electrics!

Could the hazard switch be by-passed with something else?

Anyone know a good Auto Electrician on Tyneside?

Thanks, George

[Tony B]

The hazard flashers are on a diffrent circuit to the indicator switch. The idea is that they should work regardless of what the rest of the electircs are doing. First look for a fuse. The military main light switch assuming it is a rotary type, does have a silent mode where nothing works, so make sure that is set right.. If none of that works, get back to us :-D

[Skint George]

Hi Tony.

I've just checked behind the panel and there is one fuse which is okay.

I have also checked the fuses on the steering column and they are okay too.

Checking behind the gauge panel, I noticed the Infra red switch, panel light switch and test switch without wires attached.

It's a mess behind there mate, with all the additional wire work!

None of that appears to connect to the problem switch though.

The Rotary switch possibly has had some work on it as the tail and side lights work when it is set onto "T" for tail only.

As this vehicle has had trailer lights fitted and "Blues and Two's" wired in (now removed), would they have touched the hazard switch for some reason?

I'm lost.

[Tony B]

Oh Gawd! It does sound like a nightmare. The infra red switch is best left 'Show only' .The honest answer is with so much 'helpful improvement'. :shake: it's almost impossible to diagnose at a distance. Get hold of a multi meter and wiring diagram and trace it all through is about the only answer.

Fortunatley most military Landys are wired very similar if not identical.

So on the back of the hazard warning switch

+30- power supply from fuse

+15 -to relay

r-front right indicator

l- front left indicator

31=- blank

49r- to centre wire of turn switch and flasher unit

30b-to 30b on flasher unit+49 -to +49 on flasher unit.

Hope this may be of some help.

[rambo1969]

Welcome to the wonderful world of landy wiring!!

[Guest catweazle (Banned Member)]

The infra red switch disables everything else.Dont wont you indicators going off when your creeping up on the enemy.As TB sez difficult to do from here but sure we can post a wiring diagram if need be.

[Skint George]

Thanks for the help lads!

A wiring diagram would be much appreciated.

I'll check the system over again today so don't go anywhere!

[Skint George]

Update. I'm pretty sure it could be the Hella TBB20 relay box. I can hear it "clunking" when I put the indicators on and it "clunks" when I turn the hazard switch off (no sound when I turn it on). Are these Hella relays easy to buy or would a normal relay do the job?

Yes I know I would have to change the wiring to spade connections.

[Ivor Ramsden]

Update. I'm pretty sure it could be the Hella TBB20 relay box. I can hear it "clunking" when I put the indicators on and it "clunks" when I turn the hazard switch off (no sound when I turn it on). Are these Hella relays easy to buy or would a normal relay do the job?

Yes I know I would have to change the wiring to spade connections.

 

A standard relay won't fit the plug-in connector. You need the military type. They are available new from Hella but they are a bit expensive. I nearly died when I was told the retail price but then my local Hella dealer realised they'd had one on the shelf for donkey's years so he did me a good deal. They turn up on ebay now and again for £20-£25 but I don't know how they tolerate the Post Office's handling. Try and substitute it with a known good one just to make sure it's the relay that's at fault before you buy.

[Skint George]

Hi Ivor. I couldn't be 100% sure its the relay due to being an electrical thicko but I would guess this is the problem. So how much is a new military relay and who was your stockist?

I was going to cut the old one off tonight before the rain started but I noticed it had 5 wires plus an earth wire (my "spare" relay only has 5 points). I only have two weeks before the MOT so I need it sorted now.

Anyone got a spare for sale?

George

[Ivor Ramsden]

My supplier was an auto electrics specialist here in the Isle of Man - they only had the one unit in stock. I think retail was about £40.

 

Land Rover specialists like Blanchards and Craddocks stock the relays.

 

J Richards Surplus have the Bosch equivalent on ebay now for £24.99, it's item number 360136114771

[Skint George]

Thanks Ivor.

P.A. Blanchards sell them for £46.50 ex VAT and postage. Craddocks sell them for £40 all in. Will check out that e-bay seller.

Thanks again.

George

[Skint George]

Update.

Thought I would buy the relay from Craddocks and ordered next day delivery (Friday) with Parcel Force.

Here we are on Saturday and still no Relay and Parcel force have no knowledge of it.

For anyone interested the part number for the Hella Military aluminium Relay box is 579373.

I guess you could say I'm a little bit peed off!

Moan over.

George