Military Lightweight Forum

Hello Alex,

There are many reasonably priced electrical switches at: https://www.lmslichfieldltd.com/
I bought a new hazard switch there just in case…

No matter if 12 or 24V; only the bulb changes.

Ditto for the brake test switch, a new one and only the bulb changes

How to change the mini bulb easily: viewtopic.php?f=7&t=8211

Good evening to all.
Looloo

Hi Alex,

I think that the bulb for the Hazard Light switch gets it's feed in when pressed, from the Light Green/Brown wire on Terminal 49a, which is fed from Terminal 49a of the Flasher Relay. I believe it earths via Terminal 31 of the switch to the grouped earths eyelet on the back of the speedo housing. I haven't continuity checked this to confirm, but can do if required.

Regards,

Confirmed with a spare switch this morning. The bulb holder is connected to Terminal 49a when in the 'On' position. and also connects to Terminals L and R. The bulb holder Earth is a permanent connection to Terminal 31.

Regards,

Thanks LooLoo and thanks a million Neil for checking this out for me. I will give it another check over tomorrow. Much appreciated.
Alex

Last question I hope.
Everything with the hazard switch seems to work except the bulb. But, how do I test it in the switch?
With the switch disconnected from the harness (just the button side plastic half) I have connected an alligator-clip-ended ground cable to the permanent ground 31 pin. I then connected a positive cable to 30b and these went to the negative and positive terminals of the battery respectively. Should the bulb not light up? I actually got a full power reading on the bulb connection with the bulb removed doing this... Once.
What a pain. I find this all weird as I have two switches to test with and it's the same problem on both. Also bear in mind I have actually seen one of them light up a few times.
Any ideas?

Okay, so I connected an earth to 31 and ran a positive from the battery to 49a and the bulb comes on. Hooray.
But, when the two halves of the hazard switch are connected on the loom neither on or off make the bulb come on.
When I do press the button and it pops out into the on position, the trailer turnlight warning comes on.

My red black instrument panel warning light for the indicator does not come on.

I also have a mystery spare green white cable (not the one connected into the hazard switch) that is connected to nothing, but comes out with all the other cables on the loom branch going to the hazard switch. You can see my thumb touching the spare one and my forefinger touching the one into the switch.

Hi Alex,

With the switch removed from the vehicle, connect Terminal 49a to a battery positive post, Connect Terminal 31 to the battery negative post. When operated, the switches warning light should illluminate if the switch is okay and so is the bulb itself. The bulb can be tested by wrapping a bared cable around its body with the other end of the cable to the battery positive, and touching the contact on the base of the bulb to the battery negative terminal, or vise versa.

The switch outputs can be tested by connecting a test lead with a bulb in the circuit to between Terminal 49a and battery positive, and a lead between Terminal L or R and battery negative. Operating the switch should illuminate the test lead bulb if the switch is okay. (The warning light switch will not illuminate unless Terminal 31 is still connected to battery negative.)

Regards,

Definitely some gremlins in my wiring. If I switch on the turnlight to either left or right, the indicator warning light does not come on. BUT if I then turn the 6 way lighting switch from the off position to any other position (i.e convoy,) and then back to off... The indicator light comes on.

When I then put the indicator switch back to the neutral position, the Ind wart light goes off and does not come back on when I switch the Ind back to left or right. So perhaps there is a problem with the actual 6 way internals.

Sorry Alex, you had posted again whilst I was dithering with my reply post checks.

Have you got a voltage on Terminal 30 on the Harness plug? If you have, does connecting that Terminal with a jumper wire to Terminal L or R on the harness plug light up the indicators on the corresponding side of the vehicle?

Have you got a voltage on Terminal 15 of the Harness plug with the ignition on? If so, does connecting that to Lor R illuminate the indicator bulbs on the corresponding side?

A quick check of circuits through the relay. Does connecting the Harness Terminal 30 to 30b, or Terminal 15 to 49 with a jumper wire give you voltage at Terminal 49a on the Harness plug?

Regards

Our posts crossed again mate.

Have you got a voltage on the Brown/Yellow wires at the Fusebox? This is the supply from the Six Way switch to the Hazard Light switch Terminal 30, and the Auxiliary Relay which supplies Terminal 15 on the Hazard Light switch when the ignition is on.

Regards,