Member Since: 10 Dec 2015
Location: Hampshire
Posts: 89
D3 lights 'pulsing' on startup
Hi All,
I've just bought a 2005 D3 (very happy with it so far!); one owner since new, always main dealer serviced etc etc.
It has developed (or I've just noticed; I've had it five days!) an odd problem on startup; the lights (interior and headlights) appear to pulse for the first few minutes of running.
This suggests to me a battery/alternator issue.
Anyone got any thoughts?
Thanks
10th Dec 2015 10:53 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
Welcome!
It does sound like a power issue, so get out the multimeter and check the alternator, battery and the ground connections.
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 10 Dec 2015
Location: Hampshire
Posts: 89
Thanks for the speedy reply Robbie!
So, I'm checking the battery voltage before I start it, and then the output voltage from the alternator? Where am I checking the ground connections - continuity?
10th Dec 2015 11:15 pm
camtheman
Member Since: 29 Nov 2013
Location: UK
Posts: 18
I've had this. It'll be overcharging - you may also notice the radio cuts in and out on the same rythm as the lights pulse. Check battery connections and consider a new battery. Ive had 2 AGM batteries thinking expensive equals best but have come to the conclusion Disco 3s fry them too fast so reverted to normal heavy duty acid at half the price.
You can check if overcharging by logging into the secret menu and watch the voltage after start up. My radio started pulsing on/off when the voltage was hitting 15.5v whilst revving
14th Dec 2015 9:17 pm
sailingaway
Member Since: 10 Dec 2015
Location: Hampshire
Posts: 89
Thanks camtheman!
I must confess I've been a bit ill so haven't been out with the multimeter - I'll try and do this tomorrow.
If I interpret correctly, the expectation is I'll see a super high charging voltage, and the solution is a new battery?
How do I enter the secret menu?
Thanks!
14th Dec 2015 11:47 pm
Hocks172
Member Since: 29 Mar 2014
Location: Brighton
Posts: 556
Hi i had a similar issue with the pulsing etc and it was a loose ground connection from the battery negative to the body, the nut was loose. Its easy to get to with the battery out and behind the engine fuse box.
Just incase its the same problem?
previous LR D3 HSE, RRS HST, RR Evoque Dynamic Lux.
Current D5 HSE Lux
15th Dec 2015 12:01 am
camtheman
Member Since: 29 Nov 2013
Location: UK
Posts: 18
sailingaway wrote:
Thanks camtheman!
I must confess I've been a bit ill so haven't been out with the multimeter - I'll try and do this tomorrow.
If I interpret correctly, the expectation is I'll see a super high charging voltage, and the solution is a new battery?
How do I enter the secret menu?
Thanks!
Plenty ofpposts on Disco3 mention the hidden menu if you search "hidden menu although this is probably best one http://www.disco3.co.uk/wiki/Hidden_Menu . In Vehicle Signals you'll see a voltage reading which is probably 1v lower than actual if mines owt to go by but it'll do the job and allow you to monitor from the driver seat!
You'll probably notice the voltage is quite erratic varying with revs but hitting 15.5v or even more will set the lights off pulsing and probably the audio as well. The overvoltage protection seems able to also switch Satnav off if it's bad enough. I found that switching lights and aircon off made it worse because,I assum, there was even more spare charge! If you switch absolutely everything off and the earthing/connection is really bad, you can induce the EPB warning to come on as well as the dreaded HDC warning light etc that scares the sh+t out of so many Disco3 drivers! Garages love them because they diagnose alternator failure and coin it in.
As mentioned in another post here the battery ground connection needs checking. But if all is sound there you may just need another battery - Disco3's are super sensitive to battery condition.
Occurred to me if you only just bought the car, isn't this for the seller if tthere's a warranty?[/u]
PS... If you don't have Satnav you can't use the hidden menu but there is an alternative accessed via the radio display.
15th Dec 2015 7:44 am
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
As I said, use a multimeter rather than the hidden diagnostic displays. They are too inaccurate to be of any use.
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 13 Dec 2016
Location: Devon
Posts: 3
Hi I too am suffering from pulsing headlights, I have had the alternator changed last week and this has appeared..... really annoying as have to do a lot of short journeys (4 miles) what is the best thing to start to check, voltage at battery is 12.6v when not running will check at different RPMs and see what I get.
The new alternator is rated to 150amp with a bench test cert. with an output of 14.7v.
14th Dec 2016 7:21 pm
tayaste
Member Since: 15 May 2013
Location: Chester
Posts: 7633
What brand is the new alternator?
14th Dec 2016 7:58 pm
Narpy
Member Since: 18 Jul 2011
Location: Stockport
Posts: 7830
Don't buy another battery till you're certain the alternator is doing what it should as you may very well replace a perfectly good battery with one that is no better.
It does sound like an alternator overcharge problem. Stick a meter across the battery + check the reading. Then start the car + check again. Keep it running for a short while + check again as it should slowly drop over time as the battery accepts charge.
As a quick test, try switching everything on when the pulsing occurs to see if you can make the pulsing stop. Put the heavy load items on first, heated rear screen + heated front screen and see if it stops pulsing. Mods:
Front Fogs + Halos
FBH Remote Control
The 1st Ever RRS Modded Grill
Garmin Nuvi + D4 Surround + Reversing Camera.
D4 Steering Wheel.
Rear Boot Spoiler.
Twin Brake Lights.
Wing Mirror Indicator Repeaters.
Long Roof Rails
Make your own Narpy grill thread
I'm not scared, I'm outta here.
14th Dec 2016 8:35 pm
Super chip
Member Since: 13 Dec 2016
Location: Devon
Posts: 3
Thanks for advice will do in the morning and let all know. Disco did have new battery last year by previous owner.
14th Dec 2016 8:55 pm
M3DPO
Member Since: 22 Sep 2010
Location: Notts.
Posts: 8154
Could this be caused by an AGM battery being fitted to a D3 ?It can when others can't,
It will when others won't,
It goes where others don't.
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