Headlight relay mod

[KINGPRAWN]

Just about to finish the headlight mod and am at the cutting the loom for the triggers stage.... I have read that I need to use the L/H MAIN as this activates the blue dash light??
Do I leave the R/H MAIN as it is ( still connected) or cut it too???
Also found 3 spare live terminals on the back of the fuse board for the supply ( perminant live)
These give 11.60 ish volts.. Is this enough???
Thanks.. Andy

[MidLifeCrisis]

Also found 3 spare live terminals on the back of the fuse board for the supply ( perminant live)
These give 11.60 ish volts.. Is this enough???
Thanks.. Andy

I know that other folk that have done this have run a 12v line direct from the battery to the relays for maximum results (obviously with a fuse nice and close to the battery).
If you use that live you have found at the fuse box, it will work but you will have lost a bit of voltage by using the 'original' vehicle wiring/connectors etc so you'll start with a bit of a loss.
You say that you are getting 11.6v at the fuse box, measure the voltage at the battery and see what the drop is? Then decide if you can live this - IMHO if you've gone to the trouble of sticking the relays in then you may as well run a dedicated line from the battery for max bang-for-your-buck!

[KINGPRAWN]

Thanks for that, I did wonder quite how wise this was.... Max buck bang it is then!!!

[Cruz]

11.6 volts sounds very low

[KINGPRAWN]

11.6 volts sounds very low

I did wonder!!!!
Does this mean nuffinks gettin what It ought'a!!!

[Cruz]

Considering that I read somewhere on here that going below 11.9 can damage a battery

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My started reads about 12.6 before starting then about 13.8 whilst running and drops to about 13.2 when I put the lights on and goes down even further if I put the main beam and blower on full. I assume this is due to the age of the wiring in general. I too took the relay feed from the fusebox

[KINGPRAWN]

Yeh I've got all those numbers direct from the battery but it would seem that the gremlins are dining for free within my fuse board!!

[California Dreamin]

Need I say....the whole point is to minimise voltage drop to the headlamp bulbs....
That much voltage drop needs investigating.

Martin

[billy739]

also worth noting that TD and 1.7D models do have an additional 'fat' 12v supply from engine bay to relay block on A pillar behind fuse board.

this is a direct fat feed for the 2 speed fan , there should be no problems using this for the h/lamp supply.

[KINGPRAWN]

thanks Mr Billy, mines a 2.1 but there is a relay behind the fuse box with a very heavy fuse! ill stick the meter across it and see what that says, that would save me a good few feet of cable!!

[KINGPRAWN]

So I have taken it for granted that my battery was fine as it starts perfectly and NEVER struggles, it's also not very old 2 years ish. BUT... Found the relay Mr Billy mentioned , put my meter across it and .. Only 11.60v. So back to check the battery and buggar 11.60v again!!!
So I guess this means my battery is naff although apart from the obvious rubbish lights I had no idea.

[California Dreamin]

11.6volts is barely 20% charged, your engine is going to struggle starting, so I'm suprised this wasn't more obvious.
Before writing off the battery you also need to carry out a system charge check just in case you have another issue causing the battery to go flat ie: a duff regulator brush pack, corroded battery terminal or bad earth.



Martin

[KINGPRAWN]

Thanks very much for that but new one on the way!!!
Starts perfectly on the button every time without fail...
I do have a large battery 90ah, could this be part of the problem.. 096 Bosch on its way!

[California Dreamin]

Something doesn't quite sound right....starts on the button every time yet the starter battery only reads 11.5volts? strange. Are you sure your multimeter is reading correctly?
Also...a complete stab in the dark but if your split charge relay has somehow failed (welded itself closed circuit) because of excessive current flow...it is possible that your reading is low due to a dead leisure bringing down the starter battery....I would certainly be tempted to disconnect the leisure battery terminals and check the starter again, engine turned off (possibly after you have run the engine to let it recover). See what voltage you have then at the starter battery.
Also wise to check the charge voltage (engine running) should be 13.9 - 14.2 volts across the starter battery, to make sure it is being charged correctly.

Martin

[KINGPRAWN]

Thanks for you time..... Why do things get so much bigger then the initial simple job!!!