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excossack



Member Since: 22 Feb 2012
Location: North West
Posts: 5848

United Kingdom 1999 Defender 110 Td5 SW Caledonian Blue
Headlight voltage
While changing the headlight bulbs yesterday, i took the opportunity to measure the voltage.

Engine running, no bulbs connected and light switch at position 2.
14.3v
Engine running, no bulbs connected and light switch at position 2 & bulbs connected,
10.3v

Would this be the expected results, 55w bulb causing voltage drop along the wires and switch? 1999 Defender TD5 110

Regards
John M0VAZ
Econet Station 48 no clock
Post #917913 20th Aug 2021 8:15am
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rallysteve



Member Since: 10 Feb 2014
Location: Cumbria
Posts: 2229

United Kingdom 2002 Defender 110 Td5 DCPU Keswick Green
As you have seen, you only get volt drop when current flows (V=IxR). That volt drop is far too high though, should only be a volt maximum really.

Probably the first signs of switch failure (assuming you dont have relays fitted)

Steve 02' 110 TD5 Double Cab Rebuild Thread
Post #917916 20th Aug 2021 8:30am
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geobloke



Member Since: 06 Nov 2012
Location: Nottinghamshire
Posts: 4410

United Kingdom 
That looks about normal for voltage drop with H4 bulbs on elderly wiring. This is why changing to LED headlights is such a good idea, so much less current draw on the fragile (and usually aged) Land Rover wiring loom and pathetic light switch. The older the loom gets, the less efficiently it will work, less voltage to the bulbs, increased resistance, more heat and melted switches. The other option is fitting the standalone headlight loom (such as the one by Red Bison) that uses the standard lighting loom to trigger the standalone loom that is connected directly to the battery. Protection for the Defenders loom, plus better light output. Better all round.
Post #917919 20th Aug 2021 8:34am
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excossack



Member Since: 22 Feb 2012
Location: North West
Posts: 5848

United Kingdom 1999 Defender 110 Td5 SW Caledonian Blue
Cheers both, suspected as much. I have since purchased an headlight loom but not fitted yet.
I wonder how much light I am losing....? 1999 Defender TD5 110

Regards
John M0VAZ
Econet Station 48 no clock
Post #917923 20th Aug 2021 8:46am
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geobloke



Member Since: 06 Nov 2012
Location: Nottinghamshire
Posts: 4410

United Kingdom 
A noticeable amount... Shocked When I stuck the loom in with H4s it felt like night and day at the time. Then I stuck LED headlights in and it was like turning daytime on...
Post #917924 20th Aug 2021 8:54am
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excossack



Member Since: 22 Feb 2012
Location: North West
Posts: 5848

United Kingdom 1999 Defender 110 Td5 SW Caledonian Blue
So an noticeable amount then. There are times down country lanes and unlit motorways when I wonder if my lights are actually on....
Another job to add to the list before winter 1999 Defender TD5 110

Regards
John M0VAZ
Econet Station 48 no clock
Post #917926 20th Aug 2021 9:00am
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geobloke



Member Since: 06 Nov 2012
Location: Nottinghamshire
Posts: 4410

United Kingdom 
Definitely before Winter. If you don't already have them then also think about fitting the clear crystal lensed headlamps as well. Big difference on the standard LR/Wipac quadraphotic items.

https://www.paddockspares.com/pm935-wipac-...ralia.html - Obviously there are other sellers, but you get the idea Smile

Not that expensive, but worth it come winter and country roads Thumbs Up
Post #917932 20th Aug 2021 9:28am
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excossack



Member Since: 22 Feb 2012
Location: North West
Posts: 5848

United Kingdom 1999 Defender 110 Td5 SW Caledonian Blue
Cheers, yup got them with Osram Night breakers. Just going from old headlights to new, was quite a change. 1999 Defender TD5 110

Regards
John M0VAZ
Econet Station 48 no clock
Post #917934 20th Aug 2021 9:34am
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geobloke



Member Since: 06 Nov 2012
Location: Nottinghamshire
Posts: 4410

United Kingdom 
Great combo the Crystals and Osrams Thumbs Up Thumbs Up
Post #917943 20th Aug 2021 9:53am
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excossack



Member Since: 22 Feb 2012
Location: North West
Posts: 5848

United Kingdom 1999 Defender 110 Td5 SW Caledonian Blue
They are indeed. Hopefully get the loom done over the next couple of weeks. 1999 Defender TD5 110

Regards
John M0VAZ
Econet Station 48 no clock
Post #917944 20th Aug 2021 9:55am
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jst



Member Since: 14 Jan 2008
Location: Taunton
Posts: 8038

 2011 Defender 110 Puma 2.4 USW Stornoway Grey
The switch has high voltage drop well worth running through relays. Cheers

James
110 2012 XS Utility
130 2011 M57 bespoke Camper
90 2010 Hardtop
90 M57 1988 Hardtop
Post #918073 20th Aug 2021 10:57pm
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excossack



Member Since: 22 Feb 2012
Location: North West
Posts: 5848

United Kingdom 1999 Defender 110 Td5 SW Caledonian Blue
Hi JST. Thats the plan, I have the loom, just need to get around to fitting it. 1999 Defender TD5 110

Regards
John M0VAZ
Econet Station 48 no clock
Post #918080 21st Aug 2021 7:15am
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jst



Member Since: 14 Jan 2008
Location: Taunton
Posts: 8038

 2011 Defender 110 Puma 2.4 USW Stornoway Grey
i run relays on my defenders having had a switch melt a while back started the process. voltages all much higher than the 10.5ish std. even with std bulbs difference is seen, add better bulbs and its a cheap good mod without need to LEDs etc etc Cheers

James
110 2012 XS Utility
130 2011 M57 bespoke Camper
90 2010 Hardtop
90 M57 1988 Hardtop
Post #918081 21st Aug 2021 7:43am
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dorsetsmith



Member Since: 30 Oct 2011
Location: South West
Posts: 4554



Click image to enlarge


Remove head and side lighting fuse before starting Exclamation

You will need to remove dash front and also two plastic covers in-between steering wheel and dash to get to plug switch lighting

you can mod the head light cct to add relay with out cutting in to wiring c0041 - 4 and c0041-1 have to be removed from plug switch lighting

parts needed from mod

Hard plastic 6.3mm female blade terminal cover. White qty 10

Thin wall cable 2.0mm. blue ---------- brown/ blue 2m of each ---------black 500mm long

Tin plated 6.3mm male terminal with latch 1.5-2.5m cable. qty 2

Single cover for 6.3mm male blade terminal. White. qty 2

5mm ring terminal qty 1

6.3mm female blade 1.5-2.5mm qty 10
6.3mm female blade 4mm qty -1 relay end for the two brown- blue wires that are grumped as one see pic



Click image to enlarge

This pic show lighting switch end with two 6.3mm male terminal with covers that join up with two wire removed from the plug you will need too add female covers to the removed wire ends from the plug also shows the two female terminals that fit in to the plug no cover needed


Click image to enlarge



480mm 16mm conduit to cover wiring between relay and terminal see below pic one


Click image to enlarge






30 amp automotive relay with mounting tab

I have the relay mounted under dash on right hand side and black wire and ring under fixing screw


Click image to enlarge


U = blue

NU = brown blue

b= black wire go to ground

R = 5mm ring terminal

M= Tin plated 6.3mm male terminal with latch 1.5-2.5m cable with

Single cover for 6.3mm male blade terminal

Fm = 6.3mm female blade only so that way can be fitted into plug that wires c0041 - 4 and c0041-1 removed from

6.3mm female blade with Hard plastic 6.3mm female blade terminal cover. White used at relay wire ends

check your wire and replace fuse and test side and head lights
Post #918089 21st Aug 2021 8:46am
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