I wanted to know if maybe wiring my HIDs to the battery would be better than just the normal procedure, going through the stock harness and gettign power from the alternator, etc... I ask this because I have a lot of accessories in the car (ex: TV, power inverter, PS2, radio, and stock accessories). Even though I do not have EVERYTHING on at the same time, it could be a little too much for the alternator. I plan on getting an Optima Yellow top really really soon.
So would it be a good idea? I know that HIDs need a certain amount of volts to start up (hence the upgrading of fuses), and not providing the ballast with the required amount can cause damage the ballast, as well as not supplying a certain amount of continuous power at all times. Is this a good idea? I can just wire it to a switch that is easy accessible, and would basically have my normal light switch for my corners/fogs and blinkers.
I would also like to point out that a main reason I am asking is because my car had a huge power drain a few weeks back, my car was on and idling, with basically every single accessory on, my HIDs turned off, car wouldnt start, ec... since then I have had to send back a ballast to get fixed, and my car doesnt feel like its giving back enough power, so i'm real cautious. Thanks and sorry for being so long.

Devon

 

The Alternator sees the load no matter where you wire it to.

HID lights use less energy then your stock 55Watt bulbs. Just use the factory harness.

 

umm if u connect ot battery wouldn't it still be drawing power from alternator since they are all connected?

 

I know that the HIDs are 35 watts, but I think they need a certain amount of volts to startup, from there on its less power. Thats why we upgrade the fuses, only cause of the power needed to start up the HIDs. I know that the alternator can get power from the battery, but I dont think the battery gets any power from the alternator. Regardless they both are charged when the engine is on, I figured that one less thing connected straight through the alternator would be better. I dont want to mess up the HIDs again by lack of power, thats the whole reason for all of this. I work at Sears and they told me that the alternator si fine as well as the battery.

 

I was under the impression that all the accessories run off of the battery and the alternator simply recharges it. If accessories ran off of the alternator, that would mean the headlights would get brighter as you rev and eventually fry. The battery provides a steady flow of electricity. That's why when your battery is dead and somebody gives you a jump, they recommend to keep your headlights off until it charged, as it will take longer for the battery to be recharged. Aftermarket batteries don't necessarily provide more power (volts) or electrical flow/unit time (amperes). The just have greater capacity to hold electrical charge so your alternator won't have to work as hard.

 

Hmmm you got me =/

 

when the car is running everything runs off of the alternator. when you have a high demand for current the car will actually pull from the battery for reserve power when the alternator is taxed. Your car will have plenty of juice to fire up the HIDs. you dont want to hook them directly to a battery, all you are doing is making things more difficult for yourself. That little extra kick u get when u fire up HID ballasts is not significant to "hurt" the alternator. If you're really that concerned just turn your stereo down and your ac off before you turn on your lights!

 

Cool thanks for the advice, i guess ill just start up things one at a time.

 

yup good idea, its never a good idea to give your battery a full load when it's tryin to crank the engine anyhow.

 

I just figured that this might be a way to prevent my ballasts from getting messed up in the future.

 

I wired mine up directly to the battery.. no problems here.

 

If you wire directly to the battery, it might be a good idea to use relays.......

 

I don't have any experience with hid car lights directly but speaking as an electrician i work with hid lighting alot

i'd look into/suggest :

It sounds like your voltage dropped when everthing was on and caused the ballast to drop out. Your alternator may test out fine (assuming load test) but at idle with alot on it may not deliver. Maby a high output alternator may be required.

Stock wiring harness 55w vs hid 35w :
the inrush currents may differ quite a bit. I know a ballast can require quite a bit if current to get started. Once up and running the draw will be less but it's the startup that may be an issue.
I assume there is a ballast kick (draw) everytime the lights are switched on and to and from high beams. While it works fine if the wires were undersized the failing ballast may be an indication of undersized wiring. Voltage is inversly proportional to amperage (ohm's law) so if the voltage drops the amperage increases, as amperage increases things get hot and burn out/up.

for example:
stock lights - 55w, 14.4volts = 3.81amps
stock lights - 55w, 12 volts = 4.58 amps
stock lights - 55w, 10 volts = 5.5 amps
stock lights - 55w, 8 volts = 6.875 amps

My thought on the rebulit ballast:
Wiring fine once up and running. (55w , 12 volts = 4.58 amps )
vs hid's ( 35w , 12 v = 2.91 amps ) so we have 1.6 amps to spare on the stock wiring.
In the real world the alternator should put out 14.4 so
stock are 3.81 amps and the hids are 2.43

It's the inrush current to the ballast that may need to be looked at.
Due to the ballast failure already i'd say the wiring supplying the ballast is too small. The undersized wire would cause the voltage to drop and the amperage to rise.

What was the amperage of the stock fuse ? What does it need to be changed to for hid ?

Turning off the a/c and the stereo may allow everything to startup and run but it isn't solving the problem or any problem that will bo coming down the road.

Hope this helps, Martin

 

Wow that was a great summary, Im not sure I really understood it fully, but I really do appreciate your help. To answer your last but easiest question, the stock fuse is 15, but is recommended to upgrade to 25, which is what I did. Normally, the only things I do have on when I turn on the lights are the radio (bass on real low) and the air conditioning. Im guessing that the wires that need to be upgraded are the ones from the stock harness to teh alternator, but that would be a real pain, which is why I suggested the battery idea, because if I did need to upgrade, i can just get the wire and run it to the battery, without messing with other wires and what not.
The problem with the ballast was that it would turn on (not all the time though), and eventually would just turn off by itself, this only happened to one ballast though. I cant even say that the HIDs would turn on at the same time, there would be a slight difference between each firing of the HID (id say half a second or so, but very noticeable). If you have any other questions ask and I'll try to answer. So what should I do?

 

I'd be easier to understand after 40 weeks of schooling

Anyways. Changing a 15 to a 25 is quite a jump. I can assume you haven't changed the wiring that the fuse supplies.

Have you ever blown the 25a fuse ? or the 15a fuse ? What else is supplied by the fuse ? ( a/c ? )

How is are the ballasts wired in ? Do they get there power from the stock light socket ? (through the stock wiring and the switch on the wheel stock)

Assuming they get there power from the stock light sockets.
I'd run a wire from the battery (or a suitable power block) fuse it to protect the wire (in case of short or ballast failure) and through a relay under the hood. Then the stock wiring headlight socket would activate the relay. This would allow you to repalce the 25a fuse with the proper 15a fuse.

At work I run into lots of people who replace the breaker for the garage circut with a larger one to run a compressor. The problem is that when a larger breaker is installed the wire can become the fuse. Drawing more current through a wire that it's designed for causes heat and heat causes fires.

If you were to have a short or some other problem on that 25a fuse it could cause more troubles because i'm certain nissan only put in wire made to carry 15a. The fuses are a instant blow type so any potential damage to devices or wiring would be minimal. The potential is there though.

With the relay setup the car can be left as nissan intended.( the load will be decreased as it takes far less power to run 2 relays opposed to 2 stock lights) and heavier wires fused at a higher amperage could supply the ballasts. Heavier wire means less voltage drop.

HID's sound like an expensive setup ($600 saw on another thread) so i'd venture to say a little extra wiring shouldn't be much of a burden.

On another note:
How big is the wire supplying your amps ?(i assume in the trunk). I was into car audio quite a bit. I had a HK 260 and the bass tightened up alot when i put in a #4 welding cable to it. (the fuse on the amp was a 30)

Martin

 

Well, the fuses that I upgraded were those specifically to the headlights, nothing else. I have not blown any fuses at all. Right now the HIDs are connected through the stock wiring harness, meaning that I use the stock light switch to turn them on and off. Now that I think of it, the wires that are connected to the stock harness are very thin, same as all maximas. Id say my speaker wire might be a little more thicker. Maybe upgrading wire would be a good idea for these kits, but then again, I dont want to run wire all around the car through the alternator, which is why wiring them to the battery sounds like a good idea.
Now for my amps for my system, I am running 4 gauge wire all around, fixing my capacitor so should have that in soon. Hope that gave u some more info

 

Good that the fuse only supplies the lights. I had a look at the lights + hid site also. There was a how-to on installing hid's in bmw and they were using the stock wiring system.

Looks like it may be common to use the stock system wiring for hid.

On the other hand it can't be normal to have to turn down your stereo and turn off the a/c to get them fired.There must be something about your car that needs to be adjusted/corrected.

You may need to experiment. If your hid's won't fire with the stereo + a/c on via the stock harness. Try wiring them to the battery and see if they will fire (a/c + stereo on). ( Note : the site mentioned when testing to secure the pos wire and 'switch' the negitive wire - don't know why but i'd take there word for it). This test would determine if the fuse and stock wiring is able to deliver.

I seem to think you may want to consider your alternator (hunch) amperage/voltage delivery under load. You may have a weak one ?

Will give it some more thought, but for now it's bedtime

Martin