crubrexus

Hello All,

I've just installed a XD HID system into my 05 GX. The instructions provided by Tony were excellent, and I'm thankful for the work he did in documenting everything with pictures. I'd like to point out one potential problem with these instructions, and open this to discussion from anyone interested. It has to do with tie-wrapping insulated wires against metal edges. The XD kit has insulated wires which are also sleeved in a second insulating tube, however my instincts tell me that in a vibration-prone environment, metal edges will cut through both layers if the wire is pressed tightly against the edge. This is why holes in sheet metal with wires passing through them should have a rubber or vinyl grommet. You can see an example of this in one of Tony's photos, shown here:
https://www.clublexus.com/forums/att...id=47404&stc=1

Note that the wire is tie-wrapped against the edge of the large metal cutout. With time, there is a chance that that wire will short out as the metal slowly cuts its way through, probably resulting in blowing the fuse in the XD harness, and loss of headlights until the short is repaired and the fuse replaced.

I'm not trying to be negatively critical in pointing this out. It's a subtle thing which may or may not be a problem. I felt it was worth discussing here.

Pat

robinzon

Hmm.... this is a rather prolonged discussion of a rather simple issue with equally simple solution: don't tie the tie-wraps so tight as to cause your insulation to be pressed tightly against the edge. Besides most edges are rolled and should not be sharps. Also, I would like to point out to you that in order to actually CUT through rubber you would need a very sharp edge with a lot of pressure. Rubber STRETCHES when pressure from a dull edge is applied, unless your car acts as a shaving Razor on weekends...

crubrexus

I've some experience in this area. You'd be surprised what a pressure + vibration + time will do to insulation. I don't believe that the sleeve or insulation is rubber, both seem to be PVC. I've actually run my finger along the edge in question, and I feel it is sharp enough to cause damage in the long term. Some forms of insulation, such as teflon, will actually migrate away from points of contact when subjected to vibration and steady pressure.

I'm not saying this is a definite failure waiting to happen. In my opinion, it represents a small but real risk. If you are doing an install, it's generally better to tie-wrap to locations without edges, or wrap it with many layers of tape before tying it down. You can tie-wrap loosely, but in some instances the wire can get pulled (say if the ballast comes loose), and the tension on the wire can introduce the pressure on the edge and later failure.

I'm just one of those guys who likes to be careful, and is respectful of Murphy's law (I've designed many electrical circuits and systems). I also think it's important to address because the XD kit has a failure mode in this case where both lights go out (not just one).

Pat

JWS3

already intended to avoid this, but the warning/advice remains very valid for all.

robinzon

Well as far as the both lights going out, I would suggest not using the relay harness all together (I am sure many will start the useless discussion trying to prove that the ballasts draw extra voltage and other nonsense) but simply plug each ballast directly into the vehicle harness avoiding the need to run wires from the relay (alternatively you can get a second harness - and just run the power wire from it to the battery in the back of the compartment or use adifferent power tap). Also a piece of rubber of foam is cheap to get and place under the wire. BTW: I have my ballasts connected directly to the harness.

GGGXXX

To reduce chance of failure ie. both headlights going out - - does it makes sense NOT to use the relay in XD HID and just connect the ballasts to the OEM harness....? At least the 2 headlights are independent in that case...

What is the down side of this...also has anyone used for this for extended period to test it......Clearly it would be better not to rely on one relay that may go bad........

robinzon

There is a number of people who have ran HIDs w/o the relay... some are as high as 24k on their lights w/o any problems. If its a high quality ballast I don't forsee the problem. Again you can use TWO relays if you so wish, the downside is that you will have to run another power cable to the battery (from the second relay( - but in fact it does not matter since you are running a long cable from the relay in the kit anyway so you might as well run a power cable though I would do it in the back of the engine compartment away from the elements. As a matter of fact since I am now considering installing HID fogs I will probably do just that using two realys bsides this way the second FACTORY light harness will have a place to hook up instad of hanging free..

I am runnin my LOWs directly from factory harness again I don't forsee problems.

Check other lexus forums many GS/IS/ etc. owners don't use a relay.

crubrexus

Here are a few speculations on possible reasons why an isolation relay (as shipped by XD) might be a good idea:

1) Inrush current: Many electrical circuits have an initial surge of current when they are powered up. This current spike can be pretty high, so although the HID only draws 35 watts in the steady state, it's peak current when powering up may be enough to damage the contacts of the factory relay, after some time. (24K Miles is a fairly long time, but if you want to go on empirical data, you'll need a lot of samples, or installations, to conclude that it's not going to have a significant chance of failure). The best way to judge this is to look up a data sheet on the ballast, or measure its input current with a fast oscilloscope, then compare this peak value with the ratings on the relay.

2) Input Inductance: If the ballast (switching circuits + transformer) looks largely inductive at its input, and it doesn't have protection diodes, it will spike to a large negative voltage when the lights are switched off. This voltage can far exceed the 12V system in the GX. If it is large enough, it can arc across the relay contacts as they open when the lights are switched off. This again can lead to long-term failure as carbon builds up on the relay contacts.

I agree that XD really should have included two relays in their kit, since if the single relay fails or you get a short, or if the wires are pulled out, you will lose both headlights. You can try to remember to quickly switch on your hi-beams or fogs. I personally don't like the thought of this as my wife sometimes drives our GX, and I'm sure she'll be disoriented and trying to figure out what to do.

I'm guessing that the factory relays are probably rated for something like 10 amps. I didn't check the XD relay, but I'd guess that it's about 30A. Not a whole lot more margin since it switches both headlamps, but probably a heck of a lot cheaper than the Lexus parts. If I can make the time soon, I'm going to wire in 2 30A Bosch automotive relays, and remove the cheap Chinese relay that's in the kit.

This brings to mind another suggestion I have on the install: Tie wrap the XD relay so that it can't pull out of its socket. The socket doesn't grip the relay tabs very tightly, and if there isn't slack in the wiring leading up to the relay, it may slowly wiggle its way out with time and vibration.

Pat

JWS3

Also asked if, as Robinzon suggests, we really don't need them at all. I'll post an answer/response when received.

One more thing- Someone here mentioned that the relay supplied is so-so quality. Is this true? Makes little sense if the rest of the kit is high quality. Failing/crappy relays would be something one would think they'd want to avoid. If we were to use a different relay, like the Bosch one suggested, how would we connect the leads to the ballasts? I see what appears to be dedicated connectors. Would we have to cut the leads and solder them onto the "new" wires?

Capirato

I've had HIDs on my 2004 GX for two years and do NOT use any relays. Each ballast connects directly to the power for the individual low beam headlight.

~ Cap

JWS3

Also, how do you think yours compare to the xenondepot units, which use Phillips components?

Capirato

Jim.....

All I can say is that the kit has worked flawlessly for the past two years and was very easy to install. A true, Plug and Play. No relay or having to string wires from one side of the engine compartment to the other. Nor having to connect anything to the battery nor looking for a place for a ground.

I purchased the kit from www.ProXenon.com .

Only thing I regret, is that I don't have 4300K.

~ Cap

Tony

I just sold my GX and took out the Xenondepot kit that was in my GX after two years. There was not one scratch on the cables where I zip tied them to the factory holes.

The cable housings did not show any type of wear in two years. I am sure your concerns are legit but I think it would take over 10-15 years at this rate to start any scratches on the cable housings from vibration let alone splicing them.

Also when I zip tied them to the factory holes I did not squeeze so tight as to have them pressed up against any sharp edges. Just use common sense and the kit will do its thing.

Enjoy them

GGGXXX

Tony,
What do you think about not using the relay at all per discussion above ....ie. use XD 4300 ballast but do not use the relay.....my issue is safety of using single relay vs the existing two for OEMs...and unlike others i will probably not use 2 relays....i'm sure i'll screw something up in the engine compartment and want the minimal hassels

..is there really a big exposure/ downside of simply connecting ballast to harness without the relay........seems like some others are not using a relay with no 'side effects'.....

JWS3

I've been reading with much interest the discussions regarding which kit and how to best wire it, etc. While I like the xenondepot kit, its use of a relay is a major concern--yet something else to break. If it does, say good bye to both headlights!
I saw Capirato here uses the Proxenon kit, which has no relay(s) and seems to be made very, very well. Super high quality connectors, very "OEM" in appearance and true plug and play. One downside, at least up till now, has been the lack of a 4300-4500K H11 unit. This may no longer be an issue.
Just yesterday I got an email from them telling me that they now have a 4500K GE bulb kit. Here is the text of the email:

Hi sir,

We do offer H11 system in 4500K GE Bulbs. And this new item is on special right now. Please call us for detail!


Lighting Technology & Industrial Power

I will be calling them tomorrow to see what they have. Gotta say--no relay, no battery connection and two sperate units looks appealing, even if it does cost a little bit more. Still, I'd rather pay a bit more for a better unit.

What do you guys/gals think?

JIm