Why is my low beam a 9003 bulb?

[kylejenson]

2008.5 MS3 sport points to having an h7 bulb, but for some reason they don't work but a 9003 does. I got my car used with 20k from a Mazda dealer and it came with the 9003 bulbs. They don't fit the headlight housing so it causes them to rattle when (sort of) clipped in and I've gone through like 3 bulbs in 6 months. I read somewhere that 9003s and h4s are the same or similar, but that's sort of irrelevant.

I want to convert to HIDS but since I should be converting from h7 I'm a little nervous. I know NOTHING about electronics and necessary wattage, voltage, etc.

[I gotthatzumzum]

Either Sylvania's website is down right now or my work computer sucks (which is normal, unfortunately) but if I had to take a guess, I am going to guess that since you do not have the factory HID bulbs, they are not h7. Are you looking at the low beams or high beams? My 09 came with factory HID's and they were D2S bulbs. I can't remember what my high beams were off the top of my head because I changed them so long ago... a quick google search looks like 9003 is a dual filament where an H7 is not? Take a picture of the 9003 bulbs that are in your car and I will see if I can help you out. As far as the wattage and voltage goes, you don't really need to worry too much about any of it, other than some people have problems with the 55 watt HID kits melting harnesses or the whole headlamp assembly. I find the 35W kits are plenty bright for me.

[kylejenson]

Originally Posted by I gotthatzumzum Either Sylvania's website is down right now or my work computer sucks (which is normal, unfortunately) but if I had to take a guess, I am going to guess that since you do not have the factory HID bulbs, they are not h7. Are you looking at the low beams or high beams? My 09 came with factory HID's and they were D2S bulbs. I can't remember what my high beams were off the top of my head because I changed them so long ago... a quick google search looks like 9003 is a dual filament where an H7 is not? Take a picture of the 9003 bulbs that are in your car and I will see if I can help you out. As far as the wattage and voltage goes, you don't really need to worry too much about any of it, other than some people have problems with the 55 watt HID kits melting harnesses or the whole headlamp assembly. I find the 35W kits are plenty bright for me.

I read the gen 1s come with an HID-D2S or H7 low beam and a 9005 for high beams. I double checked and my high beams are in fact 9005s. And I took a pic of the 9003 low beam bulb..

[WagonR]

H7 is the correct bulb for the low beam on your car. The thing is, H7, H4, 9003 are all similar at the base. The H4 and 9003 have three prongs at the back, and the H7 only has two, as the H4/9003 are dual filament and the H7 is single. The plug in your car will plug into all three bulbs. It looks like someone just replaced the bulbs in your car with the wrong ones, which is also why the 9003's are a little loose. The easy fix would be to go get some H7s, throw them in there and be done.

If you want to do HIDs then you can just buy the H7 kit and be on your way. Personally I'm not a fan of putting HID bulbs into halogen reflectors, and would recommend a retrofit, but that's not really what you're asking in this thread.

[kylejenson]

Originally Posted by WagonR H7 is the correct bulb for the low beam on your car. The thing is, H7, H4, 9003 are all similar at the base. The H4 and 9003 have three prongs at the back, and the H7 only has two, as the H4/9003 are dual filament and the H7 is single. The plug in your car will plug into all three bulbs. It looks like someone just replaced the bulbs in your car with the wrong ones, which is also why the 9003's are a little loose. The easy fix would be to go get some H7s, throw them in there and be done. If you want to do HIDs then you can just buy the H7 kit and be on your way. Personally I'm not a fan of putting HID bulbs into halogen reflectors, and would recommend a retrofit, but that's not really what you're asking in this thread.

The first time I went to replace the bulbs I bought h7 and noticed only two prongs, and they didn't work when I plugged them in, since they all have the same plug in maybe it was an anomaly.

As for HID, that's my main goal. I have read the halogen reflectors make the HIDs reflect weird and it's kind of an asshole thing to do because of blinding other drivers. So you think it's better to rig up different reflectors? Not just buy a new housing?

[franz]

Originally Posted by kylejenson The first time I went to replace the bulbs I bought h7 and noticed only two prongs, and they didn't work when I plugged them in, since they all have the same plug in maybe it was an anomaly. As for HID, that's my main goal. I have read the halogen reflectors make the HIDs reflect weird and it's kind of an asshole thing to do because of blinding other drivers. So you think it's better to rig up different reflectors? Not just buy a new housing?

Buying HIDs for most halogen housings is an asshole move because they reflect light in all directions. Our low beams use projector lenses that are similar to HID housings and only project the light downwards and to the right which wont blind oncoming traffic. There are some mods you can do to the housings to make the light output better if you want, but its not necessary. Check out The Retrofit Source.

I have the DDM 35w H7 5000k HID kit. The light output is almost pure white(just a small hint of blue) and lights up the road much better than the halogen bulb.

[WagonR]

Originally Posted by kylejenson The first time I went to replace the bulbs I bought h7 and noticed only two prongs, and they didn't work when I plugged them in, since they all have the same plug in maybe it was an anomaly. As for HID, that's my main goal. I have read the halogen reflectors make the HIDs reflect weird and it's kind of an asshole thing to do because of blinding other drivers. So you think it's better to rig up different reflectors? Not just buy a new housing?

That's odd that the H7s that you bought didn't work. Is there a chance that the plug from the car was upside down when you tried them? At this point it's almost moot if you're planing on going HID.

For HIDs; buying headlamps that are HID from the factory, or retrofitting in new projectors really is the ideal solution. Yes, you can run HIDs in the halogen projectors, and yes, it's better than running HIDs in a halogen reflector bowl, but it's still a compromise in light output. A retrofit is likely cheaper than buying new HID headlamps (even if you pick up a used pair).

Here's a kit that might help with the retrofit:

http://www.theretrofitsource.com/com...l#.U6pYG4m9LCQ

The years are weird though...if it was gen1 I would expect them to start before 2009. You could always call and ask. Spend some time reading about retrofits and you'll likely find a solution that works best for you.

[sidekick]

Is the actual projector assembly any different for the halogens vs the HIDs? I didn't even know that genwons were available without HIDs, but the projector still has a cut-off and would be nothing like running HIDs in a standard reflector style headlight housing.

[WagonR]

Originally Posted by sidekick Is the actual projector assembly any different for the halogens vs the HIDs? I didn't even know that genwons were available without HIDs, but the projector still has a cut-off and would be nothing like running HIDs in a standard reflector style headlight housing.

Yes, the projector is different. First, the base is different, a DS2 base doesn't fit into a projector housing made for a H7 bulb. Second, the focal point for the DS2 bulb is different than a H7, so the focal point of the projector and/or cutoff shield is different between the halogen and HID projectors. It's also likely that the halogen projector housing has a reflector to scatter some light above the cutoff shield (squirrel finder) for street signs, and the HID projector would not.

Only GT gen1s had HID, all the other MS3s and many other models from the mazda3 lineup came with halogens.

I'm not saying you HAVE to change projectors (via retrofit or HID headlamp swap), but a HID projector for HID bulbs is always a better choice than a HID bulb in halogen projector.