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Changing your 7/9 instrument lighting to LED

miguel.760ti

New member
Joined
Nov 6, 2008
Location
Mesa, AZ
Originally seen on Brickspeed

So you're an owner of a 1992 740 and you do alot of night driving, but you have noticed that the stock yellow/green-ish lighting is not only dull to look at it can also be kind of harsh at full brightness. On another long, lonely drive home one night you find yourself wishing you could change your lighting from meh to awesome. I'm gonna show you how to do it.

Step 0 - before anything you need to determine what direction you want to go with your lighting. Do you want to be flashy like all the honda kids in your neighborhood or do you want something subtle and easy on the eyes?

Step 1 - Make your way to Super Bright LEDs and browse around, they have everything from instrument cluster bulbs to LED strips to even household replacement bulbs!

Step 2 - Time to get serious, for the instrument cluster you're going to need 4 wedge base bulbs #194. There are a few types available ranging from 1 high powered LED to 6 wide angle LEDs. I went with the 5 wide angle LED (WLEDx5). They'll set you back about $4 a piece and are available in several colors. I chose red. *note - x will be the color LED you choose*

Step 3 - You're also going to need a twist-lock base LED as well, T1.5xHP #74 with the high-powered LED, you don't want a dim-spot at the top of your speedometer. <s>For 90 under 740 you're going to need two of these LEDs.</s> You don't need the extra bulb if you have a 90 under car. thanks 1989volvo740gl

Step 4 - Now after a couple days you'll get your nice LED's in the mail enclosed in cute red baggies. Now comes the fun. Click yourself over here for a guide on how to remove your instrument cluster.

Step 5 - After following the above guide you will see about 36 different twist-lock light bulb sockets. Don't freak out, you'll only need to remove 4 (or 6 depending on year). Just twist the socket counterclockwise 90 degrees and the socket & bulb will come free.

Step 6 - The 4 (of your possibly 6) bulbs simply pull right out of the socket, the LEDs press right into place. Direction doesn't matter with these as they aren't polarized (meaning you can't install them backwards).

Lucky Step 7 - Now for the two twist-lock base LEDs. On 90 under 740 there's two that go on either side of the speedometer, 91+ 7/9 there's only one that goes way up at the top in between the two larger bulbs for the turn signal indicators. Twist the base 90 degrees counter-clockwise, the base & bulb come out together. The twist-lock LED installs the same way, except you will twist it 90 degrees clockwise, however this LED is polarized (meaning that it will only light up when power is at the positive lead and ground is at the ground lead) unlike the rest. Unfortunately you won't know if it's in right or not until you plug it back in.

Step 8 - As the saying goes, assembly is the reversal of removal. However do not button everything back up completely yet as you want to be able to tell if your new LEDs work or not right?

Step 9 - Plug all your instrument cluster connectors back in and flip your lights on. If all your lights come on and dim with the rheostat you are done. If not pull your cluster back out and check your connections and LEDs.

Step 10 - Enjoy your nice new lighting that is (probably) different colored than stock and easier on the eyes. This is one of those mods that will make people wonder "Wow I wish my car had fancy colored dash lights!"

If you want matching switch trim order 5 or 6 of the 74-x wedge base LEDs. On 90- 740 these LEDs plug and play, you need one LED per switch bulb. 91+ cars use the same bulbs however you'll have to yank the stock bulb out and solder the new LED into the factory socket. This is what I did:

i - Remove the switch trim, be careful with it, it can be delicate. Start from the side away from the steering column and gently pull the trim away.
ii - Remove the bulb from its little light guide, it pulls right out.
iii - Now carefully bull the bulb & socket out of the wiring harness. Be especially cautious of pulling the wires out of the connector.
iv - Here comes the fun, twist the existing bulb around in its socket. However do not pull on it, you'll see why in a second.
v - After twisting on the bulb for a little bit it should fall right into your hand! That's what we want as we're going to solder the leads from the LED to the old bulb leads.
vi - Now get yourself a utility knife, a dremel, a pair of dykes (sidecutters) or a small hacksaw and carefully cut around the top half of the socket (above the ridge. Be careful that you don't cut through the leads of the old bulb, otherwise you're really gonna have to ghetto rig this. Now is also a good time to get your soldering iron out to get it warm.
vii - Business time, get your LED and carefully straighten the leads outward so you can solder it to the old bulb leads. Once that's done, carefully steady the bulb and socket so you can get some tin (rosin core solder) flowing for a nice, solid connection. Try not to melt the plastic socket.
viii - This step is optional, but if you have access to a 9v battery and some extra wire check your work before putting it in the car.
ix - Plug your bulb in and check that it comes on and dims with the rest of the lighting.
x - Once everything is in check, wrap a little electrical tape around your handywork and button the trim up. You are done.

If you're not sure how to cut the old socket refer to these pics that Natural244 posted, credit goes to him for doing this first.
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CameraZOOM-20120203171510612.jpg


Changing the color on the heater controls is also just as easy. Unfortunately this walk through only applies to 91+ 7/9. I'll update it when I play around with an older 7. For this conversion you will need two 74-xHP3 wedge base bulbs (again x represents the color you choose), these LEDs are special as they have a 360 degree beam, which is what you'll need to get even lighting for the controls. If you want to change the color of the halo rings around the recirc/AC buttons get two more of the 74-xHP3 of your choice.

Uno - Carefully pull the trim off that goes over the climate control module (it's probably a good idea to do this while you're changing the switch lighting over to LED as well)
Dos - Remove the 4 screws that hold the climate control module into the dash.
Tres - Carefully pull the controls out of the dash and unplug the two connectors at the back.
Cuatro - At the top of the unit there is a black plastic plate that is held in with 2 screws. Remove the screws and gently pull the cover off.
Cinco - Now you'll be able to see the prewired twistlock sockets that contain the bulbs. The two were changing should have black leads going into the sockets.
Seis - By now you should know how to remove the twistlock sockets, so remove them and pull the little bulb out. Replace with the LED (which is polarized as well so you may have to pull it back out and flip it around if it doesn't light up)
Siete - If you're changing the color of the halo rings around the recirc/AC off buttons, those bulbs also have prewired twistlock sockets. Removing those is the same as removing the main control lighting.
Ocho - Famous last words: Installation is the reverse of removal. Just don't button everything up tight yet as we still have to check our work!
Nueve - Turn your lights on and make sure it all works. If it does great, you're done. If not, pull it back out and flip the LEDs around.

Enjoy your lighting!

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Good times. In my experience (91 740) reading the guide to make sure you buy the right bulbs is essential.

Oh, and just bend the tabs. You'll know what I mean.

Edit: Oh, and +1 on the eBay LEDs suck. My fender marker went out after a day.
 
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just submitted my order - gary was very helpful with my questions and i chose cool white for a stock upgrade look.
 
Okay, I'm here to make a quick addendum to the heater control LEDs for a '91 740 without Automatic Climate Control.

Quick picture from my Instagram as an overview of my finished product;
http://instagram.com/p/YlDDtlkww-/

I chose green, because racecar.

Oh yeah, the big difference is, the lights (LED bulb NEO4xHP) are located on top of the control unit, directly behind the faceplate. They are two flat twist-in bulb-and-holder assemblies, you take them out the same as the top-mount lights in the speedo. Twist CCW, remove assy, replace with light, check polarity. If all's good, throw the old bulbs away and enjoy!

Edit: also, Green is terrible at illuminating redlines, but illuminates needles well enough! Just so you know!
 
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Now, I've been at this a couple of times myself with little success.. (on a 1995+ 960) thing is - I want WHITE instrument cluster/switches/ECC/etc. lighting. So how would one remove the green film/paint from the dials? If I were to swap the bulbs for leds I'd only get blue, so far the only places that needed no modifications are the el. window/seat heater/trans mode switches.
 
Okay, I'm here to make a quick addendum to the heater control LEDs for a '91 740 without Automatic Climate Control.

Quick picture from my Instagram as an overview of my finished product;
http://instagram.com/p/YlDDtlkww-/

I chose green, because racecar.

Oh yeah, the big difference is, the lights (LED bulb NEO4xHP) are located on top of the control unit, directly behind the faceplate. They are two flat twist-in bulb-and-holder assemblies, you take them out the same as the top-mount lights in the speedo. Twist CCW, remove assy, replace with light, check polarity. If all's good, throw the old bulbs away and enjoy!

Awesome. I never got around to messing around with other cars so this is good info.


I was originally inspired to do this when I saw your thread Jesse.
 
Anyone got any tips for securing the bulb behind the slide-y heater control on the older 740s? For whatever reason mine doesn't stay in, and electrical tape isn't a very good solution so the light keeps falling out behind the heater controls. :lol:
 
Anyone got any tips for securing the bulb behind the slide-y heater control on the older 740s? For whatever reason mine doesn't stay in, and electrical tape isn't a very good solution so the light keeps falling out behind the heater controls. :lol:

Solder it into place. Need to remove it, heat up the solder again. Done.
 
I'd like for you to edit step 3 if you could. My '89 required four of the WLEDx5 194 base bulbs for the gauges like you stated, but the two T1.5xHP #74 bulbs are for the turn signals, not for the speedometer. You were correct about the base, but they are actually the turn signals. I'll have a picture up tonight when it gets dark.
 
I'd like to update my results. I did this about 3 years ago, and nearly all of the single led small guys for the heater controls, sunroof, antenna, etc switches have burned out. The cluster ones are still fine.
 
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I'd like to update my results. I did this about 3 years ago, and nearly off of the single led small guys for the heater controls, sunroof, antenna, etc switches have burned out. The cluster ones are still fine.

Just out of curiosity, did you pick up your LEDs from Super Bright LEDs, or from some other reputable source, or otherwise?
 
I've heard a few burnouts say they've had super bright lighted LEDs. :omg: :-P

Actually, I've had many of their bulbs and never had any issues at all....over several years' time. My 245's have been in for over 4 yrs and they're still going.
 
I've heard a few burnouts say they've had super bright lighted LEDs. :omg: :-P

Actually, I've had many of their bulbs and never had any issues at all....over several years' time. My 245's have been in for over 4 yrs and they're still going.

*related*

they offer a warranty for 3 yrs now, you just have to read the fine print!

*unrelated*

....... mother of god, you have had a lot of volvo's .......
 
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