I have an aftermarket steering wheel and the auto cancel on the indicator turn signal rarely works properly. Being an noise filled environment I can't hear the indicator relay clicking, so I often leave the indicators running by accident.

I added loud buzzer, here is the mini project write up.

 

ADD AN AUDIBLE TELLTALE BUZZER TO A LANDROVER DEFENDER

 

Scope:

Mini project to add a loud audible warning tell-tale to a Landrover Defender

indicator signal because they are easily left on without self cancelling.

Parts list:

4x 3amp 1N5400 silicone diode (or similar) (Maplin Order Code: QL81C, £0.18 each)  

1x 12volt miniature buzzer (Maplin order code: FL40T, £1.99)

Pair of insulated automotive bullet plug connectors. (Maplin order code JH86T) £1.29

for a pack of ten. (Or you can splice into loom instead)

Strip of electrical insulation tape .

Piece of 40mm x 40mm plain hole matrix circuit board. Not essential but gives a

firm base to mount components on.

2x 100mm lengths of small gauge automotive wire. One Green and one Yellow if

wishing to follow the same colour code as standard UK trailer socket wiring for

(yellow)left and (green) right indicators.

Tools:

Soldering iron and solder.
Wire cutters.
Needle nose pliers for shaping diode legs.
Wire strippers.
Crimping tool for the Bullets.
Screwdriver to remove the LandRover rear quarter light panel.

Circuit Diagram:

Layout Diagram:

Just a suggested layout, wire it how you like, do not even need to mount on a board just as long as everything is connected correctly and safely insulated where needed.

Method:

Build circuit as per diagram. Take care to place the diodes in the direction shown

and ensure the buzzer wires at connected in the correct orientation. Insulate the exposed bare metal parts with the insulation tape.
<<place holder here for photos of finished article>>

Installation:

At the rear of the Defender, inside behind the offside light cluster cover are

the connector blocks for attaching a trailer hitch socket wiring loom to the

stock loom. Push the green wire bullet connector into the relevant right hand

indicator block and the yellow bullet connector into the left hand indicator

block. <<Place holder here for LR wire colour detail>>

Testing:

Turn on ignition and try the indicator. The buzzer should sound and the indicator

lamps still function correctly. Try the other direction indicator. The buzz should

sound as per other side. Try the hazard lamps, the buzzer should remain silent.

Review:

Even though it is located in the rear of the truck behind a panel, the buzzer is

still loud enough to be easily heard over engine noise.