Help Sorting Tail Light Wiring!
#21
04-12-2016, 09:43 AM
That's good: you have battery voltage on one side. The residual ~2V on the other would drop if a bulb was in circuit.
Agreed replace them both. The ones on the 'bay are metal film which will be most likely on a ceramic substrate. I think that they will do the job.
If you want to check further while they arrive, you could put temporary wire bridges across where they are located in the SLM. You'll get a message when you brake, but at least you will be able to use the car.
Mike
Agreed replace them both. The ones on the 'bay are metal film which will be most likely on a ceramic substrate. I think that they will do the job.
If you want to check further while they arrive, you could put temporary wire bridges across where they are located in the SLM. You'll get a message when you brake, but at least you will be able to use the car.
Mike
I ordered the resistors and they will be here in a couple of days.
I will post any updates between now and then
Thanks!
#22
04-12-2016, 12:01 PM
So I went ahead and bridged those resistor locations.
I now have 12 volts across the board
Looks like those resistors I just ordered will do the trick and I will have this SLM sorted and my tail lights all up and running.
Next on the list is sorting out the lights themselves.
Need to find a set of "switchback" led's to use for the reverse and the indicators but I want to know something.
The hyperflash correction resistors that are available online for LED lights. Are those, in any way, jeopardizing the work I just did to the SLM?
They all seem to be claiming they are 50w resistors @ 6ohm
Just want to make sure I do not damage the SLM any further.
I now have 12 volts across the board
Looks like those resistors I just ordered will do the trick and I will have this SLM sorted and my tail lights all up and running.
Next on the list is sorting out the lights themselves.
Need to find a set of "switchback" led's to use for the reverse and the indicators but I want to know something.
The hyperflash correction resistors that are available online for LED lights. Are those, in any way, jeopardizing the work I just did to the SLM?
They all seem to be claiming they are 50w resistors @ 6ohm
Just want to make sure I do not damage the SLM any further.
#23
04-12-2016, 03:01 PM
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What you are trying to achieve is to fool the SLM that you have a working, incandescent lamp in place, so you need to match the current draw of that lamp.
The 6 ohm resistors will be fine for the brake circuit, but a pair of tail lamps (they're twinned in each cluster in the later cars) will draw about half as much as a single brake lamp. You need to load each tail lamp with about 12-15 ohms. Drop much below that and you're going to be pushing the ones you've just replaced.
Something like this for the tail lamps:
LED Rear Light Ballast Resistors X2 for Range Rover Sport 2010 Lamps Upgrade | eBay
Easy life!
Mike
The 6 ohm resistors will be fine for the brake circuit, but a pair of tail lamps (they're twinned in each cluster in the later cars) will draw about half as much as a single brake lamp. You need to load each tail lamp with about 12-15 ohms. Drop much below that and you're going to be pushing the ones you've just replaced.
Something like this for the tail lamps:
LED Rear Light Ballast Resistors X2 for Range Rover Sport 2010 Lamps Upgrade | eBay
Easy life!
Mike
#24
04-20-2016, 07:53 PM
So,
The SLM is now completely repaired and its all back together.
Waiting on a set of switchback LED bulbs to complete the indicators
I was wondering if there is a way to determine with more accuracy how much resistance I need to apply to the tail lights? The park and brake lights do throw a warning on the dash but I don't want to add to much resistance to each circuit. Just enough so that the system believes there are bulbs in there.
Ideas?
The SLM is now completely repaired and its all back together.
Waiting on a set of switchback LED bulbs to complete the indicators
I was wondering if there is a way to determine with more accuracy how much resistance I need to apply to the tail lights? The park and brake lights do throw a warning on the dash but I don't want to add to much resistance to each circuit. Just enough so that the system believes there are bulbs in there.
Ideas?
#25
04-21-2016, 04:01 PM
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Bernie,
It's not really that critical, and you're likely to have difficulty getting exact values.
Assuming a single tail lamp is 12V 5W, and a brake lamp is 12V 21W, then you need a 14.4 ohm resistor rated at ~15W for the tail, and a 6.86 ohm resistor rated at 25W for the brake (and indicator to keep the BPM happy).
I've not made allowance for the LED lamp current draw in the above, but I doubt it's significant. You can measure this for each to confirm.
So, I imagine you'll be fine with 6 ohm for the brake and 15 ohm for the tail on each side
BTW, these should be attached to some form of heat sink (perhaps a piece of aluminium sheet). At least you'll have a nice warm trunk
Mike
It's not really that critical, and you're likely to have difficulty getting exact values.
Assuming a single tail lamp is 12V 5W, and a brake lamp is 12V 21W, then you need a 14.4 ohm resistor rated at ~15W for the tail, and a 6.86 ohm resistor rated at 25W for the brake (and indicator to keep the BPM happy).
I've not made allowance for the LED lamp current draw in the above, but I doubt it's significant. You can measure this for each to confirm.
So, I imagine you'll be fine with 6 ohm for the brake and 15 ohm for the tail on each side
BTW, these should be attached to some form of heat sink (perhaps a piece of aluminium sheet). At least you'll have a nice warm trunk
Mike
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razorboy (04-21-2016)
#26
04-21-2016, 09:35 PM
Bernie,
It's not really that critical, and you're likely to have difficulty getting exact values.
Assuming a single tail lamp is 12V 5W, and a brake lamp is 12V 21W, then you need a 14.4 ohm resistor rated at ~15W for the tail, and a 6.86 ohm resistor rated at 25W for the brake (and indicator to keep the BPM happy).
I've not made allowance for the LED lamp current draw in the above, but I doubt it's significant. You can measure this for each to confirm.
So, I imagine you'll be fine with 6 ohm for the brake and 15 ohm for the tail on each side
BTW, these should be attached to some form of heat sink (perhaps a piece of aluminium sheet). At least you'll have a nice warm trunk
Mike
It's not really that critical, and you're likely to have difficulty getting exact values.
Assuming a single tail lamp is 12V 5W, and a brake lamp is 12V 21W, then you need a 14.4 ohm resistor rated at ~15W for the tail, and a 6.86 ohm resistor rated at 25W for the brake (and indicator to keep the BPM happy).
I've not made allowance for the LED lamp current draw in the above, but I doubt it's significant. You can measure this for each to confirm.
So, I imagine you'll be fine with 6 ohm for the brake and 15 ohm for the tail on each side
BTW, these should be attached to some form of heat sink (perhaps a piece of aluminium sheet). At least you'll have a nice warm trunk
Mike
I will run with your suggestion
Bernie
#27
05-02-2016, 02:05 PM
So I got to wiring everything up today and have run into a snag.
There is only one ground wire running to each side for the lights in the rear. I attached all sides of the 3 resistors I am using together and tied them to the single ground (park, turn and brake) - all LED.
When I started wiring the other side of each resistor to their respective positions, I started getting weird fluttering on the LED turn signal. Haven't gone through the rest yet until I get this resolved.
The other side I used some test clips / cables to try the indicator and this time of course I only had one resistor in circuit. The turn on the other side works perfectly.
So my question is:
Is the system / resistors on the other side seeing some sort of "collective" resistance since all of the resistors are attached to the same ground wire? Trying to wrap my head around this as all the grounds come together at some point regardless?
To reiterate:
There are 3 resistors mounted to a metal plate that I fashioned (for park, brake and turn signal).
Since there is only 1 ground headed up to the tail lights, I tied one side of all three resistors to that ground and then it breaks out to the grounds of each of the 3 LED lights.
The other sides of the resistors feed each of their respective lights independently. (1 to the turn, 1 to the brake, 1 to the park)
BTW - The fluttering of the turn signal occurs with no other lights on. I get a slow flash on the dash but the light flickers like a strobe.
There is only one ground wire running to each side for the lights in the rear. I attached all sides of the 3 resistors I am using together and tied them to the single ground (park, turn and brake) - all LED.
When I started wiring the other side of each resistor to their respective positions, I started getting weird fluttering on the LED turn signal. Haven't gone through the rest yet until I get this resolved.
The other side I used some test clips / cables to try the indicator and this time of course I only had one resistor in circuit. The turn on the other side works perfectly.
So my question is:
Is the system / resistors on the other side seeing some sort of "collective" resistance since all of the resistors are attached to the same ground wire? Trying to wrap my head around this as all the grounds come together at some point regardless?
To reiterate:
There are 3 resistors mounted to a metal plate that I fashioned (for park, brake and turn signal).
Since there is only 1 ground headed up to the tail lights, I tied one side of all three resistors to that ground and then it breaks out to the grounds of each of the 3 LED lights.
The other sides of the resistors feed each of their respective lights independently. (1 to the turn, 1 to the brake, 1 to the park)
BTW - The fluttering of the turn signal occurs with no other lights on. I get a slow flash on the dash but the light flickers like a strobe.
#28
05-02-2016, 03:29 PM
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Might just be a dud LED...
Other thought - do the indicator lamps definitely not have an integral resistor?
Mike
Last edited by michaelh; 05-02-2016 at 05:10 PM. Reason: clarification
#29
05-02-2016, 05:36 PM
Quick rap on the lens and it stopped.......lol.
So I have good indicators, stop lights and the backup lights work well.
I do have an issue with the park lights.
The lights work but I am still getting a "check bulb" indication on the dash and after a few minutes of leaving them on, the resistor gets mighty hot.
I used my temperature probe to keep an eye on it and after about 5-7 minutes of leaving them on, the resistors went over 200F.
So not sure what direction to take on this? The resistors are mounted on their own metal plates and attached to the metal of the bodywork of the car so I am not concerned about melting anything but how hot can these resistors get?
Kinda moot on that resistor because I obviously do not have enough resistance to stop the bulb check on the dash.
I don't get it with the brake though and I do not have a hyper flash with the turn indicators either so I am almost there.
#30
05-03-2016, 11:14 AM
I ordered another set of 10ohm resistors.
Figured if they worked on the brake lights, they might work for the park lights too?
Jury is still out on the temperature thing though. Although I have them isolated and mounted to metal, I feel nervous for the SLM and the resistors themselves running at temps over 200F for extended periods of time such as the park lights would.
Figured if they worked on the brake lights, they might work for the park lights too?
Jury is still out on the temperature thing though. Although I have them isolated and mounted to metal, I feel nervous for the SLM and the resistors themselves running at temps over 200F for extended periods of time such as the park lights would.
#31
05-03-2016, 03:35 PM
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Hi Bernie,
I rechecked my maths just in case..
For each pair of 5W tail lamps (=10W per side), a 15 ohm resistor should have done the trick.
Since you've ordered some 10 ohm resistors, then obviously try this, but it may point to more damage in the SLM current sensing than just the pair of 1 ohm resistors you've already replaced.
Heat: Bear in mind that each of the resistors across the park lamps is pretending to be two 5W bulbs. It's going to dissipate at least 10W for the lie to work, so it will get hot; it has been constructed with this in mind and 200F isn't surprising. Only cure here is a bigger heat sink.
The brake and indicator ones will heat even more, but as they're only in use intermittently its much less obvious/an issue. Note that the 10 ohm resistors will dissipate ~15W each and should be rated at 25W to give a comfortable safety margin.
As for the SLM internal resistors, even with a 10 ohm load they'll still be well within their rating.
Please do report back.
Best,
Mike
I rechecked my maths just in case..
For each pair of 5W tail lamps (=10W per side), a 15 ohm resistor should have done the trick.
Since you've ordered some 10 ohm resistors, then obviously try this, but it may point to more damage in the SLM current sensing than just the pair of 1 ohm resistors you've already replaced.
Heat: Bear in mind that each of the resistors across the park lamps is pretending to be two 5W bulbs. It's going to dissipate at least 10W for the lie to work, so it will get hot; it has been constructed with this in mind and 200F isn't surprising. Only cure here is a bigger heat sink.
The brake and indicator ones will heat even more, but as they're only in use intermittently its much less obvious/an issue. Note that the 10 ohm resistors will dissipate ~15W each and should be rated at 25W to give a comfortable safety margin.
As for the SLM internal resistors, even with a 10 ohm load they'll still be well within their rating.
Please do report back.
Best,
Mike
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razorboy (05-05-2016)
#32
05-05-2016, 09:57 PM
Hi Bernie,
I rechecked my maths just in case..
For each pair of 5W tail lamps (=10W per side), a 15 ohm resistor should have done the trick.
Since you've ordered some 10 ohm resistors, then obviously try this, but it may point to more damage in the SLM current sensing than just the pair of 1 ohm resistors you've already replaced.
Heat: Bear in mind that each of the resistors across the park lamps is pretending to be two 5W bulbs. It's going to dissipate at least 10W for the lie to work, so it will get hot; it has been constructed with this in mind and 200F isn't surprising. Only cure here is a bigger heat sink.
The brake and indicator ones will heat even more, but as they're only in use intermittently its much less obvious/an issue. Note that the 10 ohm resistors will dissipate ~15W each and should be rated at 25W to give a comfortable safety margin.
As for the SLM internal resistors, even with a 10 ohm load they'll still be well within their rating.
Please do report back.
Best,
Mike
I rechecked my maths just in case..
For each pair of 5W tail lamps (=10W per side), a 15 ohm resistor should have done the trick.
Since you've ordered some 10 ohm resistors, then obviously try this, but it may point to more damage in the SLM current sensing than just the pair of 1 ohm resistors you've already replaced.
Heat: Bear in mind that each of the resistors across the park lamps is pretending to be two 5W bulbs. It's going to dissipate at least 10W for the lie to work, so it will get hot; it has been constructed with this in mind and 200F isn't surprising. Only cure here is a bigger heat sink.
The brake and indicator ones will heat even more, but as they're only in use intermittently its much less obvious/an issue. Note that the 10 ohm resistors will dissipate ~15W each and should be rated at 25W to give a comfortable safety margin.
As for the SLM internal resistors, even with a 10 ohm load they'll still be well within their rating.
Please do report back.
Best,
Mike
Looks like you may be right - again.
The 10ohm resistors came in today so I clipped them into the setup and no love at all. Check Rear Lights still comes up on the dash when I put the park lights on.
Looks like more issues with the SLM but that's it for me for now. I didn't notice any other burned out components on the SLM when I inspected it and there is not much left on that PCB that I could change out anyway with my tools and skill level.
So my indicators work without hyperflash and my brake lights do not trigger a bulb warning. I am going to live with the other warning as I need to move on to more important things with the car. I will circle back to this issue once I get further ahead on other things.
Next on my list is:
Transmission service
Replace plastic thermostat housing assembly
Front and rear brakes
Front shock mounts
Tie rod ends
Convertible headliner
Weather stripping around windows
Repair headrest motor cables
Reinstall seat modules in their new cases
Probably a lot of other crap I haven't discovered yet lol.
Not a huge list but still.......................
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