Lightforce XGT's not as good as they should be.

[davez104]

Hi all,
Having a few problems, (I think), with my new set of Lightforce XGT spotties. They were installed at an ARB shop so should be done properly. The problem I have is that they are not as bright as I think they should be, I have ridden in a mates car with a set of Blitz 240's and they where plenty brighter. With the car idling and the lights on, I am measuring about 12.8V at the battery and 11.5V at the lights, with the car on about 1000rpm, I get 13.5V at the battery and 11.8 at the lights. I have checked all the main power connections and none of them seem to be a problem. Checked resistance between all points and no dramas there either. The wires that supply both power and earth to the spotties run very warm when the lights are on, as does the relay. Could the wiring be just too small? They used a Lightforce instalation kit, so you would reckon they would be up to the task. Could the battery be on its way out? Would this cause these problems? Measured output at the alternator, at idle, is a bit over 14V.

Anybody have any other ideas?
Thanks.
Dave.

[rustynuts]

The problem your describing is in the wiring, either the wrong guage cable has been used ie too small or you have an earthing problem. You should have roughly the same voltage at the lights as you do at the battery.
Possible causes:

a) All connections tight
b) Check cable size (I use 4 mm from battery to relay and from relay to light overkill maybe but every volt you drop you reduce the light output by *@#& loads.
c) Earthing to the lights (check that the earth is an earth)
d) Faulty relay high resistance contacts. (has happend to me)

I have no doupt that if you can get that voltage to where it is suppose to be youll be frying roos before you get near them.

[davez104]

Thanks for that, I've measured the resistance between the +'ve connector that goes on the battery, through the relay (switch closed, as if lights where on), through the fuse, to the plug that goes into the back of the lights, measured 0.7 Ohms, which is about right I think. The earth wire goes from the lights straight to the -'ve terminal of the battery and the resistance measured the same. All conections are tight, no corrosion, and appear to contact well. The only thing I can think of is to up the wire size, might be worth playing with to see what results I can get. I'll be a bit p!$$ed if the Lightforce installation kit is not capable of running these lights, could have wired them myself a hell of a lot cheaper, $55 for the kit and $90 to have someone fit them.

Thanks.
Dave.

[AussieGQ]

Turn the lights on and put your multimeter probe on the positive terminal of the battery and the other probe on the positive wire as close to the spottie as possible.
This will so you the exact voltage drop on the cable.
You could also test the relay with this same method to see if it has a problem

[ausoops]

take it back to arb and tell them to fix it.

[davez104]

With the lights unplugged there is no voltage drop at all, with them pluged in and the wires running hot, the voltage drops heaps, the further along the circuit I check, the more it drops, up to more than 1.5V from battery to lights. I'm going to get some heavier guage wiring and give that a shot.

I would take it back to ARB, but the shop that fitted them is 700kms away, I'll have a crack, myself.

Thanks.
Dave.

[BowTieGQ]

Also, as wire heats up it becomes less conductive, then heats up more and you get the picture. Use 6mm wire on everything. Picture it like a hose. The only restriction then would be your workmanship. But been your car, I'm sure you'll be more carefull.

[stevo_K]

Also, as wire heats up it becomes less conductive, then heats up more and you get the picture. Use 6mm wire on everything. Picture it like a hose. The only restriction then would be your workmanship. But been your car, I'm sure you'll be more carefull.

i agree, i have 2 ralle 4000's and 2 ralle 1000's used 6mm wire for the whole job. i also run seperate power and earth wires to each light using duel 87 pin relays. i have enough light to light up a small town. 4000's on 1 switch and the 1000's on another.

cheers steve

[turps]

Might also be worth just testting the lights at night. With them directly conected to the batt (ie dont test on road). Then you can use what ever wire you have floating around (even 400amp jumper leads will do).

[bazzle]

take it back to arb and tell them to fix it.

Fault is in the supplied loom not the fitting. If it gets hot wire gauge is too small.
Just double up the feed from batt to relay, easiest fix.

Bazzle

[HotFourOk]

take it back to arb and tell them to fix it.

Fault is in the supplied loom not the fitting. If it gets hot wire gauge is too small.
Just double up the feed from batt to relay, easiest fix.

Bazzle

As said, it could be a dodgy earth also. That's not a loom issue. You think Lightforce would supply a loom plenty big enough for thier own lights... considering how much you pay for them.
Some people have had this happen mounting to bad earths on bumpers, bullbars etc.

[bazzle]

take it back to arb and tell them to fix it.

Fault is in the supplied loom not the fitting. If it gets hot wire gauge is too small.
Just double up the feed from batt to relay, easiest fix.

Bazzle

As said, it could be a dodgy earth also. That's not a loom issue. You think Lightforce would supply a loom plenty big enough for thier own lights... considering how much you pay for them.
Some people have had this happen mounting to bad earths on bumpers, bullbars etc.

Then the earth point would heat up not the wire.

BAzzle

[bogged]

You think Lightforce would supply a loom plenty big enough for thier own lights..

have you seen the human hair thats used as wire on the 240's?

[davez104]

OK, so the wiring is all done. Used 6mm (50Amp) wire for both earth and power, from the battery, through the 30Amp fuse, 70Amp relay, through to where I had to split into two wires, one for each light. From there I used 4mm (15Amp) wire. I am now measuring a 0.16 Volt drop from battery to lights, slightly better than the 1.7 Volt drop I was measuring before, Yes that is an improvement of 1.54 Volts!! Looking forward to taking them for a drive tonight. I compared the cross-section of the wire that had been used and it is smaller than the 4mm, very close to 3mm, which is only rated to 10Amps. I think these lights will draw around 8Amps each, so trying to push 16+ Amps through that was never going to work. Still want to get the best out of them, so here's a few other measurements. At idle, with spotties on I get 12.50Volts at the battery, at 1100rpm, it gets up to 12.89Volts, turn the spotties off and gets up to around 13.5Volts. I know the alternator cranks out over 14Volts so could this mean the alternator is getting a little sad with its output? (Even though I can still measure over 14Volts at the back of the alternator)

Thanks.
Dave.

[CRUSHU]

You will have voltage drop from the pissy little Toyota wire from the alternator to the battery.
Replace it with a real cable, or double it up with another wire.

[MQSWBUTE]

i recon your wiring is 2 small also you said the relay gets hot maybe you need a bigger relay

i do simple setups no relays just from the batt to a heavy duty switch never have problems no heat nothing only thing is im running higer amps inside the car alot of people dont like that idea which i can understand

[davez104]

How do you dip your lights for oncomming traffic with no relays? You don't run all that current through the factory lighting swithes do you?

Dave.

[MQSWBUTE]

only use the spotlights off road they are not tapped into the factory wiring
(i dont mess with factory stuff beside cdplayers)

wire from battery to switch and then from switch to spotlight flick on and off

[DIRTY ROCK STAR]

and the result?

[MQSWBUTE]

good flow of power never had a problem for me a relay is just a thing to pack up good wiring will last a long time ( good connectors soildering heat shrink etc)


of course in the setup i would use a aftermarket narva fuse box when you start going alot of things without relays you would run a big const power cable to the block and have smaller feeds running off that

heres a very simple diagram

[r0ck_m0nkey]

good flow of power never had a problem for me a relay is just a thing to pack up good wiring will last a long time ( good connectors soildering heat shrink etc)

A good correctly sized relay will do the same. Benefit of a relay is that you can place them anywhere to reduce the cabling length for the switched load (a good thing) They don't just come in those small black plastic ones, if you want something a little more solid in construction.

They built a 4WD once and didn't use relays to switch things, was called a Lada Niva, the most electrically reliable vehicle ever made

[davez104]

Took the Patrol for a drive last night, the lights are a fair bit brighter, but the light is also a lot whiter than it was. You can really notice it with the spread beam, it lights up the side of the road heaps better now.

Thanks for all the help.
Dave.