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PostPosted: Wed Dec 13, 2006 5:22 pm
by Simba
toayoztan wrote:Okay with the pic above, those are the different bulb types i ran into when changing and looking at the cluster bulbs and HVAC bulbs. Can you identify the bulbs there that are unknown? They look smaller than 74...or are they still 74? I believe the gray socket base is used for lighting such as fog light button. The smaller black one at the right is used for the HVAC.

The small bulbs in the twist-lock bases in the instrument cluster are #74. The smaller ones, with the flush screw-head base are also #74 bulbs, but they are not a conventional type. I believe these are Toyota-specific bulbs that have the bulbs permanently attached to the base. For these, you cannot use a #74 led, and must instead pull the bulb out of the twist base, and solder up a LED/resistor replacement.

I'm going to do this next, so, I'll document the process.

This picture shows (and i what i know heh) that there are only 4 microbulbs illuminating the entire HVAC. They are the small microbulbs you see in the 1st picture i posted, at the far right of the pic. Would we still order 74 bulbs for those??

No, for those you will need to make a custom LED based on the original base. I'm going to do this and will post instructions-- it's fairly straightforward. The only location you can use the #74 LED bulbs, either with the bases, or the regular spade sort, is on the back of the gauge cluster for the caution/warning lights. The rest of the twist-lock bulbs for the HVAC, et al, are a custom job.

Also Simba, when you talked about ordering 74 wedge bulbs, which ones exactly did you mean? They showed 3 kinds.
1) T1.5 Instrument LED bulb - 74 bulb with socket base
2) B8.3D Instrument Cluster LED bulb - another kind of 74 bulb with socket base
3) 74 Wedge Base LED bulb - just the 74 bulb alone without socket base

I got the 74 Wedge Base bulbs and put them in my existing #74 sockets. You could also get the T1.5 bulbs with the bases, which would simplify the install somewhat. The B8.3D's will not fit in anything.

The microbulbs can't use the 74 bulbs w/o a socket base, so which socket base 74 bulb should we order?

Either the T1.5's, or just get the wedge bulbs and use your existing sockets.

And which bulb should we order for the smaller mircro bulbs used in the HVAC?

Any small 3mm wide angle LED in the color you desire. However, one should note that the lighting of the HVAC will probably not be as uniform using LEDs.

PostPosted: Wed Dec 13, 2006 5:40 pm
by Simba
bigacuralvr wrote:B8.3D Instrument Cluster LED bulb - another kind of 74 bulb with socket base

I don't believe these will work, as they have a different socket than what Toyota uses. You want the #74 bulbs with the T1.5 base, or just the #74 wedge bulbs.

I know the wedge base bulbs fit, so that's what I recommend people order.

PostPosted: Wed Dec 13, 2006 8:48 pm
by toayoztan
Cool, thanks Simba.

A note/question about the gauge cluster still though. So i understand that the gauge cluster uses 74 and 194. However, only like half or so of the 74 bulbs have a wedge bulb, and the other half are as you already noticed are the flush type customized by toyota.

It's no problem, i can just order the T1.5 74 bulbs that come with sockets to replace those, right? I think that's what i understand from what you are telling me.

Oh, but that makes me wonder...does that mean all your 74 bulbs on your gauge cluster had removeable 74 wedge bulb and socket base? Just curious is all, I thought you maybe would have had some that you had to replace with T1.5 74.

Also, for the HVAC, i also figured it out too that 74 wouldn't fit. So what i did (which was mentioned earlier from someone else) was grab some microbulbs from RadioShack, unwrapped the wiring off the socket base of the old bulb, wrapped the wiring around the socket base of the radioshack micro bulbs, and that worked out fine. They dont' have red, so i will probably order the bulb covers bigacuralvr gave us a link to, probably double up the covers to make them deeper red, and hopefully they should match the red leds from the gauge cluster. Problem is, the radioshack microbulbs aren't as bright as the OEM bulbs (go figure). So i will probably just order new OEM bulbs from 1sttoyota, take the green covers off, and slap the new red covers on. That way, i get brighter and brand new OEM bulbs that are red.

I dont' want to use LED's in the HVAC as i alreadly presume and know that no LED that will be able to fit in the microbulb socket will illuminate (wide enough anyway) to get eveness across the HVAC. And bright spots really annoy me, but it's personal preference.

Thanks again Simba!

PostPosted: Wed Dec 13, 2006 9:33 pm
by Simba
toayoztan wrote:Oh, but that makes me wonder...does that mean all your 74 bulbs on your gauge cluster had removeable 74 wedge bulb and socket base? Just curious is all, I thought you maybe would have had some that you had to replace with T1.5 74.

All of my #74 cluster bulbs had the spade-type base socket on them. The only thing that has the flush bulb sockets are the HVAC controls, et al, at least in mine. You should be able to pop in the T1.5's just fine if you have flush bulbs in yours.

I dont' want to use LED's in the HVAC as i alreadly presume and know that no LED that will be able to fit in the microbulb socket will illuminate (wide enough anyway) to get eveness across the HVAC. And bright spots really annoy me, but it's personal preference.

Actually, I found some (relatively) low power 180 degree LEDs that should do the trick without any hotspotting, so I guess we'll see.

I did my Supra cluster years ago with conventional narrow focus LEDs and it worked out great, though there's considerably more space for the LEDs to light in that design than in the AT.

PostPosted: Wed Dec 13, 2006 10:11 pm
by toayoztan
Cool, let me know how those 180 degrees work out for you. If you don't plan on getting around to it soon, just let me know what they are and i can order them to try them out as i'll have some time over the xmas break into january before school starts again, and let you know how it goes too.


PostPosted: Thu Dec 14, 2006 5:06 am
by toayoztan
Alright i ordered Red bulbs. I'll let you guys know how it goes too and take some pics!


PostPosted: Fri Dec 22, 2006 7:23 pm
by Aaron
Looks great! Now put some gas in that thing!

PostPosted: Fri Dec 22, 2006 8:51 pm
by Simba
Aaron wrote:Looks great! Now put some gas in that thing!

It has plenty. A working fuel level sender, however...

PostPosted: Fri Dec 29, 2006 6:12 pm
by Simba
Okay, entirely more than you probably wanted to know about LEDifying the HVAC lights.

First off, a few things of note: I had planned to use some 5mm 360 degree white LEDs for backlighting the HVAC controls, however, upon making the things, I found that 5mm leds will not fit into the backlight holes, so I had to use 45 degree conventional white LEDs. The results of this were lackluster, so the search is on for 180 or 360 degree 3mm white LEDs. Fortunately, the backlighting bulbs are fairly easy to replace.

I'll step through this in the various parts that need to be done for a full conversion: The door window switches, the fog light button, HVAC board, and defrost button.

I should also point out that while changing the backlight bulbs to LEDs of whatever color is fairly easy, doing the rest of the OEM LEDs in the door switches and HVAC buttons is a complete, royal PITA. If you want to do it, prepare for pain.

This is what you get when you're done. I used red LEDs for my "on" HVAC buttons (except the AC button, which is blue) and white 45 degree backlighting LEDs.



As I said, the backlight LEDs fairly well suck save for the one spot behind the heater control in which it shines straight through. Once I find some better LEDs, it should all look like the heater control.

First off, the window switches. After you completely disassemble the door panel, you will be able to remove the switch box. There is a third screw that holds the box in, and in order to get it you have to remove the pull handle from the door panel itself. Then, you can pull the switch box apart, which is a fairly trivial matter. However, when you rip it apart, parts will go flying, so do it on a large, clean desk or table. The flying parts in question are typically the two contact points for the switches themselves. If you are extremely unlucky, the passenger window lockout button will come apart on you as well. It takes about an hour of swearing to get it back together if it does come apart, so DO NOT press the button with the switch box apart.

Once disassembled, you'll have this:


There are two circuit boards for the LEDs under the switches. In the above photo, I've removed one. They are held in with melted plastic pegs. You will have to cut the heads off and gently pry the boards up to remove them.

When you have the boards out, you can desolder the original green LEDs, like so:


This is a blue LED put into the board. Note that POLARITY MATTERS, and the LED can only go in one way. Fortunately, Toyota labeled every circuit board that uses a LED with the correct flow polarity. The annode of the LED (longer prong) goes on the arrow side of the diode symbol, not the bar side. In this photo, the annode (positive) lead is on the top.


Once you're done, you can secure the boards back into the switch box with a few dabs of epoxy on top of the old plastic pegs. Be sure and test the boards once installed, as putting it all back together only to find out they don't work would pretty much suck.


Finally, you can put everything back together, and get this:


... more to follow in the next post.

PostPosted: Fri Dec 29, 2006 6:23 pm
by Simba
Okay, next up is the fog light switch. It has a single #74 bulb to illuminate it, so it's a fairly trivial matter to LEDify. In fact, this is the only location in which a 5mm 360 degree led will actually work. So, first, the process for making them.

First, take the old bulb and pull it out of the holder. To do this, you need to pry up the tiny bulb leads with a small slotted screwdriver, and then unwrap them from the base. You can then pull the bulb out of the holder, and replace it with a LED, like so:


(While it looks yellow, this is a 360 degree 5mm white LED.)

Then, you can bend the negative prong (shorter one) around the bulb base as normal. This is fairly easy, though a good set of needel nose pliars and a small slotted screwdriver will make it easier.


Once wrapped, you can trim the negative prong to size.

For the positive lead, you start by threading a resistor into the other side of the bulb holder. I am using a 1k Ohm resistor here, and everywhere else. You could probably go with a smaller resistor, like a 500-700 ohm, though given the fluctuating nature of a vehicle electrical system, a little extra resistance is a good idea. These are the same resistors Toyota uses on all the original LED boards, so it's a good example to follow.


Finally, you can bend the positive LED annode and the other end of the resistor into proximity with each other, and add a dab of solder:


You should now test the LED.


Even with a 1k resistor, it's still plenty bright. It's not a bad idea to put a small sliver of tape under the resistor to insulate the postive lead from the negative LED lead, which is directly under it. If you position the resistor well, you should not have to do this, but it doesn't hurt to be careful.

When you're done, it pops into the fog light housing easily:


Be sure to TEST the housing plugged into the dash before you put everything back together, as LEDs are polarity sensitive, and if you have the older in "backwards", the LED will not work. If that happens, you'll have to take the older back out, rotate it 180 degrees, and reinstall.

PostPosted: Fri Dec 29, 2006 6:34 pm
by Simba
Next up, the HVAC buttons. I cannot stress enough how much of an amazing PITA it is to do these, nor how easy it is to break them, so you should be reallyreallyreally sure you want to do it. The backlighting bulbs are easy enough, the button LEDs are not.

First, you need to pull all the backlight bulbs out of the HVAC cluster, remove the AC switch board, and finally remove the white backing plate. Once you do, you'll have this:


The 12 LEDs for the flow control button and HVAC buttons are now visible. Each small white "box" with the diode label above it is a LED. In order to change them, you need to remove this board, and in order to do that you must remove the buttons from the front of the unit, like so:


The buttons just snap into the white actuators under them. However, the plastic is very fragile and prone to snap. If you snap the little tabs off the buttons, they will need to either be replaced (good luck finding them), or epoxied on. If you epoxy them, you will never be able to take the controls apart again, so make sure you pick a color you'll be happy with if you want to change the LEDs.

The rear defrost button snaps out of the housing via two nearly impossible to get tabs, and pulls out backwards. More on this little SOB later.

Once you have the board free of the housing, it'll look like this:


You must then remove all of the white button actuators without breaking them. This is also an amazing PITA, and requires some very gentle work with a screwdriver to pop them off of the blue tabs without snapping them. I managed not to break any, but the removal process took three hours. When they're off, you can pull the clear plastic light channels off the board, and be left with the buttons and the LEDs:


In order to remove the LEDs, you need to desolder them from the back of the board, while pulling them gently out of the button holders. This is a complete PITA. Using a kelly clamp makes it a little less annoying. Once they're out, you can insert your new LEDs. Again, you must insert them with the correct polarity. Match the long positive annode of the led to the "arrow" side of the diode diagram on the back of the board.

There's one other LED you can replace, which I didn't photograph, and that's the "on" light for the AC button. It's fairly straightforward to desolder and replace it. I used blue for the hell of it, even though my AC system is presently removed. :twisted:

PostPosted: Fri Dec 29, 2006 6:43 pm
by Simba
Finally, you can do the last button, which is the most complete PITA ever imagined: The defroster button. Once you manage to remove it from the HVAC controls, you will find there are two bulbs:


One is for the backlighting of the button, and the other is for the "on" light.

Once you rip the switch apart, which is in itself a PITA, you'll see both:


The small green one is the backlight. The large one is the "on" light. Here is another place you can use a 5mm 360 degree LED, for the "on" light. I used a red LED to match the HVAC LEDs, and then used a 45 degree white LED for the backlight. It worked reasonably well in this switch, but it could be better with a 3mm 360 degree.


It's a good idea to give the contact points a good splort of dielectric grease before you reassemble the switch. Then comes the fun part:


This is the bottom of the defrost switch board, with the LEDs installed. The trick is, there is virtually no room under the defrost switch for the required resistors, due to the AC switch and how the defrost switch snaps into the cluster. The best solution would be to source some smaller resistors. I used normal sized resistors, and as a result, I had to trim the mounting sheath in the HVAC cluster slightly to clear the resistors once the switch is installed.

Also, if you get the polarity wrong, you'll get to rip the whole thing apart again and turn the LED sockets around.

All in all, I'm pleased with the results, and once I find some 3mm 360 degree white LEDs and get some tiny resistors, the backlighting should be up to par with everything else.

PostPosted: Fri Dec 29, 2006 7:23 pm
by ___Scott___
Simba wrote:The annode of the LED (longer prong)

Unfortunately this is often, but not always, true. It varies depending on the manufacturer. What is always true is that when you look inside the LED you'll see that one side is big and the other is little. The big side is always the cathode (-). In this pic, the anode (+) is the upper leg and the cathode (-) is the lower leg:

Also of note, is that the forward voltage drop across white or blue LEDs is higher than for the more common green/red/amber LEDs. Blue or white LEDs drop around 3.5V, whereas green/red/amber LEDs typically drop closer to 2.1V. The current limiting resistor you choose to use is also dependent on the nominal forward current allowed for the particular LED, which can vary typically between ~5mA to ~30mA.

PostPosted: Fri Dec 29, 2006 9:46 pm
by toayoztan
Also, another note, when taking out the rear defrost button, be SURE you are careful sliding it out. That spring Simba shows in the pic you must not lose or you'll need to get another spring.

Oh, and i'm not sure if it was mentioned, but the key halo is another nice feature to change colors on, and is very easy. It uses a 74 wedge bulb or LED. You'll need to remove the black trim piece surrounding the key cylinder, then if you look under the key halo, you'll see one brass screw. Undo the screw, the halo will slide off the cylinder, and you'll see a 74 wedge socket to undo, very straightforward.


PostPosted: Fri Dec 29, 2006 9:59 pm
by Simba
toayoztan wrote:Also, another note, when taking out the rear defrost button, be SURE you are careful sliding it out. That spring Simba shows in the pic you must not lose or you'll need to get another spring.

Yup. There's also a small ball bearing in the top of the switch which likes to pop out at light speed. I hate the rear defrost switch with a passion.