Discovery 4 electric plug behind front grill

[Wbarks69]

Hi just wondering what this plug is behind front grill ?https://uploads.tapatalk-cdn.com/20190115/63640c568dd873c3f68ca40cc5a42b59.jpghttps://uploads.tapatalk-cdn.com/20190115/b493541f218d3b6f4a4c3246fbb5db47.jpg

[DiscoJeffster]

Adaptive cruise control I thought, but don’t quote me

[Graeme]

Not conclusive by any means but it doesn't look at all similar to the blanked plug for the ACC radar unit link harness on my L322. The radar unit uses 5 wires - HS can-bus(2 twisted), perm power, ign and earth.

[LRD414]

Smog sensor not installed to Australian vehicles.

Cheers,
Scott

[Nmritchie]

I can’t comment on the intended use for the unused connector that is located centrally up high behind the grill of my Disco 4, similar to that shown in the photos on this thread, but can pass on some good advice from a Land Rover specialist.

When I was getting my crank battery replaced on a recent interstate trip I was shown that connector as a very handy source of an “ignition wire” for triggering low voltage DCDC auxiliary battery chargers.

My 2014 Disco 4 SE has keyless engine start, and when I had it setup when new, with an auxiliary battery and a DCDC charger under the bonnet, it was supposed to be wired to operate only when the engine was running.

However, it was wired to an “accessory” wire, which does activate when accessories or Start is engaged, but also activates when any door is opened and remains active until a timer shuts the accessories Off after about 10 minutes. When the car fridge has run the auxiliary battery charge down, particularly over night, whenever a car door is then opened, the DCDC charger activates to pump 25 amps from the crank battery to the auxiliary battery. It doesn’t take many door openings to flatten the crank battery, or add to battery cycle stress leading to early battery failure.

Having just returned home from that trip, I am yet to have the DCDC charger wired to the unused connector. I am told that it only activates when the engine is started, and shuts down soon after the engine stops, and NOT when doors are opened. The specialist also said that my model Discovery needs to use a Low Voltage DCDC charger, as the alternator often operates at voltages that are too low to automatically trigger most DCDC chargers.

If you have a keyless ignition Land Rover and want to run an auxiliary battery, it is essential to use a DCDC charger to properly charge it due to the low voltage “smart” alternator, and the DCDC must be a low voltage type triggered by an Ignition wire. That wire is ideally sourced from that unused connector.

If that was more commonly known, I wouldn’t have endured a few flat batteries and 3 crank battery replacements!

I will also be using that connector’s “ignition” wire to activate the relay for the Anderson plug to the caravan. It also has a DCDC charger that draws another 25 amps from the crank battery whenever I opened a car door.

I hope someone else finds uses for that mystery connector!

[kelvo]

If you have a keyless ignition Land Rover and want to run an auxiliary battery, it is essential to use a DCDC charger to properly charge it due to the low voltage “smart” alternator, and the DCDC must be a low voltage type triggered by an Ignition wire. That wire is ideally sourced from that unused connector.

Poppycock.

I have a Traxide smart isolator (USI-160) currently set to ‘ignition’ mode. Guess which battery is which from the screen shot
D4 Starter, D4 Aux and Camper Trailer. The engine was stopped 8 hours before I took the screen shot.

[Tombie]

I can’t comment on the intended use for the unused connector that is located centrally up high behind the grill of my Disco 4, similar to that shown in the photos on this thread, but can pass on some good advice from a Land Rover specialist.

When I was getting my crank battery replaced on a recent interstate trip I was shown that connector as a very handy source of an “ignition wire” for triggering low voltage DCDC auxiliary battery chargers.

My 2014 Disco 4 SE has keyless engine start, and when I had it setup when new, with an auxiliary battery and a DCDC charger under the bonnet, it was supposed to be wired to operate only when the engine was running.

However, it was wired to an “accessory” wire, which does activate when accessories or Start is engaged, but also activates when any door is opened and remains active until a timer shuts the accessories Off after about 10 minutes. When the car fridge has run the auxiliary battery charge down, particularly over night, whenever a car door is then opened, the DCDC charger activates to pump 25 amps from the crank battery to the auxiliary battery. It doesn’t take many door openings to flatten the crank battery, or add to battery cycle stress leading to early battery failure.

Having just returned home from that trip, I am yet to have the DCDC charger wired to the unused connector. I am told that it only activates when the engine is started, and shuts down soon after the engine stops, and NOT when doors are opened. The specialist also said that my model Discovery needs to use a Low Voltage DCDC charger, as the alternator often operates at voltages that are too low to automatically trigger most DCDC chargers.

If you have a keyless ignition Land Rover and want to run an auxiliary battery, it is essential to use a DCDC charger to properly charge it due to the low voltage “smart” alternator, and the DCDC must be a low voltage type triggered by an Ignition wire. That wire is ideally sourced from that unused connector.

If that was more commonly known, I wouldn’t have endured a few flat batteries and 3 crank battery replacements!

I will also be using that connector’s “ignition” wire to activate the relay for the Anderson plug to the caravan. It also has a DCDC charger that draws another 25 amps from the crank battery whenever I opened a car door.

I hope someone else finds uses for that mystery connector!

Your install was certainly incorrectly wired, however your specialist is greatly misinformed.

This is one of the biggest issues in the world of 12v

[Nmritchie]

Your install was certainly incorrectly wired, however your specialist is greatly misinformed.

This is one of the biggest issues in the world of 12v

I have just had the DCDC charger’s ignition wire connected to that mystery connector, as per the specialist’s advice. It now works perfectly! The DCDC charger now activates when the engine is started, and turns off immediately it is stopped. It does not activate on opening a door, which was the problem previously. It does activate on the “accessories” setting, by pressing START without the foot brake, but that is rarely used.

Just to recap, this is a problem with the Disco 4 with keyless Start. I can’t comment on what other models have the same issue.

So Tombie, that specialist was very well informed!

[Tombie]

I have just had the DCDC charger’s ignition wire connected to that mystery connector, as per the specialist’s advice. It now works perfectly! The DCDC charger now activates when the engine is started, and turns off immediately it is stopped. It does not activate on opening a door, which was the problem previously. It does activate on the “accessories” setting, by pressing START without the foot brake, but that is rarely used.

Just to recap, this is a problem with the Disco 4 with keyless Start. I can’t comment on what other models have the same issue.

So Tombie, that specialist was very well informed!

Huh???[bigwhistle]

Your install was wired incorrectly initially AND your specialist informed you that a DcDc was a requriement due to the alternator on the D4... How was that 'well informed'?

Its not a problem with Keyless start, its a problem with installers not understanding / adapting their thinking to suit keyless ignitions.

I only shifted to DcDc due to a Lithium install for space constraint reasons, and picked up a correctly switched trigger from the get go, with no issues at all with the system.


Glad you got yours sorted..