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Discussion Starter · #1 ·
Seeing LED bulbs that are advertised as 'error free' I decided to get LED bulbs for the 2007 XC90. Got some to replace the various 194 bulbs all over the car--the white ones in the front, amber ones on the front corners, red ones in the tail, as well as the mirror flashers, and puddle lamps.

Unfortunately the 'error free' was BS, the four tail lights triggered the bulb out message. Ideally I'd find and modify the shunts and run basic LED's, I'm not thrilled with resorting to splicing resistors and had avoided bothering with LED's until I saw these advertised as error free. Still not thrilled with the idea that there is some part of the circuit that just wastes power in order to not throw an error, but at least it was all contained in the bulb and involved no splicing (I HATE hacks). Too bad they didn't work... Also too bad I fell in love with the richer red color of the LED taillight bulb.s

So I found a solution that involves no harness splicing--I got some resistors, bent them in a U shape over the bulbs, and soldered them on the LED bulb itself. They are inside the lens and you can't see them, and prevent the error. There is about 0.375" clearance between the resistor and the bulb, and I bench tested them with a spare 12V battery to check how warm they get, and its comparable to a 194 bulb (not too hot to hold in your fingers, even when powered for many minutes).

choosing size was easy--194's are rated to 0.27A, the LED's used like 0.15A which was apparently not enough. So 0.27-0.15=0.12A, R=V/I =14V/0.12A=116ohms. I got 1W 100ohm resistors from radio shack and soldered them on. Voila, no error.

I'd prefer adding bulbs to cancel the error, might as well get some light from that wasted energy. Perhaps next I will look at some way to open up the dummy 'lights' above the tails and adding some LED's there, though odds are I will never get around to it since doing it in such a way as to look OEM while getting the total draw to equal the stock setup will be a challenge. But just wanted to post this as an FYI for anyone who wants the richer look of LED's, at least for the running lights.

Meant to take pictures, but had everything buttoned up before it occurred to me...
 

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I opened the uppers, added 3 LED strips(2 running, 1 brake) and ta-da! Position light error gone! Visual is under Tail Lights (with pics). I used white LEDs to stay as bright as possible, hoping the lens would color it. Bad idea. Get the red LEDs.
 

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Discussion Starter · #3 ·
Just checked out the thread, cool. I still have the 2007 tails, not the updated '14 style. I'd be more eager to open up and do the uppers if only there wasn't that large gap w/o light at the top of the lower tail, but we'll see.

What I was toying with was getting three sets of 10W 1157's, and converting the 1156's and 194's to those. Based on the draw of the 1157's I found, it would take 6 to have the equivalent current draw of 2 1156 stop lights, and then I would just use the 'second filament' as the tails in all three positions. But that would run like $100+ just for the bulbs, plus sockets, & tail light mods. At that point I might just spend the $400 to get the '14 tails and be done with it (though I'd have to resort to resistors for the brake lights, sigh). Will have to wait until I get a set of winter tires, change oil, coolant, ATF, and install sway bars though (getting backed up with tasks).
 

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Discussion Starter · #4 · (Edited)
Just checked out the thread, cool. I still have the 2007 tails, not the updated '14 style. I'd be more eager to open up and do the uppers if only there wasn't that large gap w/o light at the top of the lower tail, but we'll see.

What I was toying with was getting three sets of 10W 1157's, and converting the 1156's and 194's to those. Based on the draw of the LED 1157's I found, it would take 6 to have the equivalent current draw of 2 1156 incandescent stop lights, and then I would just use the LED 1157's 'second filament' as the tails in all three positions. But that would run like $100+ just for the bulbs, plus sockets, & tail light mods. At that point I might just spend the $400 to get the '14 tails and be done with it (though I'd have to resort to resistors for the brake lights, sigh). Will have to wait until I get a set of winter tires, change oil, coolant, ATF, and install sway bars though (getting backed up with tasks).
 

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I only had to use one resistor for the brake lights. I put it in the left lamp before the rubber plug between the black and yellow wires. Pulled the rectangular piece of foam out, put the resistor in the hole in the frame, then put the foam piece back in place. Still had the position light error, but the upper LEDs fixed that by accident. Zlead is planning to do continuous LEDs for the uppers. That would give more of the XC 60 look.
 

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Discussion Starter · #7 ·
Awesome, thanks. I actually have a set of ceramic 20W 8ohm resistors from another project, I guess I could use one. But still trying to track down whether I can just mod the shunt. Saw diagrams saying they're in the REM but it must be from an earlier model as mine looks different. It would be nice if I could plug n' play the '13-14 shunt into my car, but I doubt its that easy.
 

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Shunt? Maybe a picture could explain it? My tails were unplug the old, plug in the new (minus the resistor).
 

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Discussion Starter · #9 ·
The shunt is the circuit that measures load on a circuit, on our cars they are set up for incandescent load, so when you install LED's you need to use a resistor to eliminate the bulb out message. Since the '13-14's came with LED's, the shunts for the tail and brake circuits are set up for LED's, if it was a simple plug n' play on some module somewhere it would be the most elegant solution as it would require no additional current wasting resistors in order to avoid bulb out messages. I might have to get a copy of VIDA from '13 or later to see if that will help (as it is I can't find my '12 copy). I saw mention that they are in the relays or on the REM, but some light googling hasn't helped much more than that.
 

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Oh got it! I'm not that intense into electrical. I could take pictures of the backside of my lights if that would help you.
 

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Discussion Starter · #11 ·
Goodness, me neither--know just enough to get into trouble. Appreciate the offer but a picture won't help, the shunt is somewhere else on a circuit board somewhere. Hopefully not part of a circuit board, I'm hoping its something that plugs onto the board. Not a huge priority for now as I have the sways waiting to go on, and ATF coming for a flush. Also planning on changing coolant, the overflow tank has green stuff in it and I'm not sure its supposed to... so planning on getting OE-ish stuff. All this will come first, I only messed with the lights since the LED bulbs were supposed to be plug n play...
 

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It's all perfect in writing, not always the case in real life... Good luck with whatever you choose!
 

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For anyone reading this thread and also looking for LED reverse lights to replace the bulbs found in both the older style taillights as well as the newer LED taillights, I just installed these LEDs available through Amazon which are the same CANBUS error-free lights that are sold for the front parking bulbs. No errors on my dash and the light output is greatly improved over the OEM bulbs. I have tint on my windows and this helps tremendously with being able to see without the aid of a backup camera at night. These are relatively new so there were no reviews, but I'm hoping they area a long lasting solution.

http://www.amazon.com/gp/product/B01AEW730S?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s01
 
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