worth changing front turn signal bulbs?

I'm in the process of replacing both headlamps on my car, and the turn signal bulbs are 7440s. They are original, and the car is 6-7 years old. They're whatever bulbs that Lexus felt fit to install.

Is it worth changing them while I'm replacing the entire headlamp assembly? These bulbs are not really easy to access with the headlamp still on the car. As a matter of fact, I don't think they're accessible at all with the lamps on the car.

If I do change them, are there certain bulbs I should try to get? I know I should probably stay away from the parts-store Sylvania Long Life type bulbs. A long bulb lifespan is great, but I doubt these have the best photometrics. I heard Stanley bulbs are good. Any other choices? Or should I just leave them alone? My parents have a 20-year old Toyota with its original turn signals, so maybe these bulbs aren't going to die anytime soon?

Ls400 said:

I'm in the process of replacing both headlamps on my car, and the turn signal bulbs are 7440s. They are original, and the car is 6-7 years old. Is it worth changing them while I'm replacing the entire headlamp assembly?

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That kind of sounds like you answered your own question, there! As long as you have it all apart, replace them while they're easily accessed. You're right that many of the parts store bulbs are not a quality product. Here's a single Stanley 7440. Or here's a pair of Toshiba 7440 (mis-listed as "Hyundai", actually Mazda). Both are equally top quality.

(Also, you could go put new bulbs in your parents' 20-year-old Toyota to restore full brightness...)

Ls400 said:

I'm in the process of replacing both headlamps on my car, and the turn signal bulbs are 7440s. They are original, and the car is 6-7 years old. They're whatever bulbs that Lexus felt fit to install.

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Ancient bulbs.

These bulbs are not really easy to access with the headlamp still on the car. As a matter of fact, I don't think they're accessible at all with the lamps on the car.

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Reaaalllly difficult to change with the headlamps installed. Removing and replacing the headlamps to install the turn signal bulbs will require reaiming.

I'm not sure this is a question you needed to ask-- you know in your heart of hearts that you should change them while it's convenient.

My parents have a 20-year old Toyota with its original turn signals, so maybe these bulbs aren't going to die anytime soon?

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You should get them new bulbs, too. The envelopes on them may be kindof a pearlescent black by now, and they're also going to fail pretty soon.

On my '08 GX470 the front turn signal bulbs both burned out last year (6 months apart) and the cost to have them replaced was high due to the labor involved. Yes, yes, yes! Replace them!

I looked into LEDs, but they need a diode or resistor or something (I forget exactly) added to the wiring to make them work correctly, so you don't get the rapid blink (indicating a burned-out bulb) with them. There are also some LEDs sold with the added thingy built in, which is simple but pricey, about $40 each IIRC. If I'd had time to order them in and all, it probably would have been worth it for longevity.

I felt like I might have to turn in my 'man card' for hiring out a bulb replacement, but holy cow! On the driver's side they had to pull the battery and a bunch of other stuff.

Rexlion said:

On my '08 GX470 the front turn signal bulbs both burned out last year (6 months apart) and the cost to have them replaced was high due to the labor involved. Yes, yes, yes! Replace them!

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Replacing in pairs would have been a bigger hit at that time but still, annoying to have to do it again 6 months later.

I looked into LEDs

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Not all LEDs work in all vehicles for photometric reasons-- this sticky can help you determine if the replacement is safe or not.

I felt like I might have to turn in my 'man card' for hiring out a bulb replacement, but holy cow! On the driver's side they had to pull the battery and a bunch of other stuff.

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Sometimes it's just easier to let them do it. What bothers me is that people are supposed to be able to do it themselves, but on some cars it gets harder and harder to do so. You'd think there oughta be a law...

I thought about 7440 LEDs but a quick glance at the parts store selection turned me off that idea. That giant heatsink in the middle can't be good for photometrics (talking about the Sylvania Zevo).

Plus, I know that the LEDs are supposed to last "forever" but I'd rather not experiment with parts store technology. I'll stick with the proven incandescent mini bulbs. When I pulled the 9003's out my parent's 20-year-old Toyota, which has a fixed DRL function (can't disable it), they were original, Koito branded bulbs. Born 1999, end of watch 2017; they had a good run.

Ls400 said:

When I pulled the 9003's out my parent's 20-year-old Toyota, which has a fixed DRL function (can't disable it), they were original, Koito branded bulbs. Born 1999, end of watch 2017; they had a good run.

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The voltage on that system must not just be kindof low, but must have very good control of transients. It might also ride pretty smoothly, having not jarred the filaments too harshly.

Those bulbs were probably done in 2006 but nobody really realized it...

Wow, I didn't realize just how worn out my turn signals were. When I put the new and old bulb side-by-side, I thought I saw that the old bulb's capsule was slightly darker than the new one, but it could have been just a case of wishful thinking. The new bulb also appeared to have a slightly curved filament while the old one was perfectly straight, so I wasn't expecting too much out the new one.

Anyway, I put a new one in my lamp. I left the old one in the other side because I only ordered one bulb, but I'm ordering more.

I see that the new bulb projects light much, much higher than the older bulb. I suppose this is helpful for visibility-- throwing light well above the main region of the low beams?



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That cloud of light from the turn signal is way too high to be of much use; the light distribution on the right looks probably more appropriate, but please try again without the headlamps lit.

Here's without the low beams lit:





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These pics make me think there might be something wrong -- like the new left bulb is faulty or it's not fully inserted all the way into its socket, or the socket's not properly installed in the lamp. You should be seeing a more or less regularly shaped output pattern from the turn signal, brightest in the center and fading out to lower intensity at the edges. Something like what you see from the right turn signal with the old bulb. If there's nothing obvious when you take it apart again, try exchanging the two bulbs, left in right and right in left, and see what the patterns look like then.

Ls400 said:

The new bulb also appeared to have a slightly curved filament while the old one was perfectly straight

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The filament may have a little wave or very slight bend to it at each end, it but it's not deliberately curved. The example pics from the products -Virgil- linked show it's not supposed to be bent in an arc. Are you sure you got the bulbs you ordered? If you did get the right bulbs, then it's clearly an installation error. Just like a Maglite focuses by moving the reflector relative to the filament, if the light center length is not correct, the focus will not be correct.

Thanks guys, it was installation error. It took a few times to plug it in correctly, and now the beam pattern on the wall is similar to the beam pattern of the old bulb--just much more intense!

I guess this means I should probably look into swapping the taillight turn signals as well!

I had a similar issue with a similar bulb in the reversing lamps of my daughter's car. Top-quality bulb, nothing wrong with the lamp, socket properly installed, but the light was all over the place in streaks. I chased my tail about it for awhile, because the bulb sure seemed to be snapped all the way into the socket, but it went an additional fraction of an inch when I pushed a little harder...then the light pattern was correct.

Thanks everyone again for the help. I have a related question (same car, and it's about the turn signals) and decided against cluttering up the board with yet another thread. I was doing some reading and found that earlier models of the Lexus IS series come with two turn signal compartments on the front right and left. What sort of pros and cons are associated with this sort of setup? I imagine it would be all pros--can't hurt to make things more conspicuous, but I don't know.

https://www.youtube.com/watch?v=pTAzZpYWIxE

I read a little bit about turn signals below and it appears that multiple front turn signal lamps on one side are allowed, and whether they are tested together or separately depends on how far apart they are.

https://law.resource.org/pub/us/cfr/ibr/005/sae.j588.1984.html