issues install flashing module a car 3rd brake light - Page 1
Forum section: electronics / beginners

author: wojtek077
author_rank: Contributor
timestamp: July 01, 2019, 06:13:51 am
content: I'm trying to installing a flashing module for my third brake light on my car. I'm having problems with flasher working properly when car's running but when the car is in the on position it works fine. The third brake light goes straight thru a body control module. I tried putting a resistor because as the cars running voltage goes up. I thought the body control module was trying to limit the current. I think problem is that voltage goes to 3v not 0v but the same thing happens when car's in on position. I'm lost now what guys think I should do next?

author: KMoffett
author_rank: Regular Contributor
timestamp: July 01, 2019, 11:14:57 am
content: Is this a commercial after market flasher module? Link?Ken

author: wojtek077
author_rank: Contributor
timestamp: July 01, 2019, 10:40:36 pm
content: Well kinda ofhttp://www.3rdbrakeflasher.com/brake-light-flasher-c-65/universal-brake-light-flasherstrober-m1-model-p-181.html

author: Audioguru
author_rank: Super Contributor
timestamp: July 01, 2019, 11:59:10 pm
content: A flashing brake light will confuse many old grannies and they will crash into you.

author: james_s
author_rank: Super Contributor
timestamp: July 02, 2019, 12:09:41 am
content: I'm not sure how it could be confusing, I see them all over and they're certainly eye catching. The problem I see is that in the US anyway they are illegal and that means if you do get in an accident it could cause big headaches if an insurance adjuster notices you have it. Their whole job essentially is to find loopholes to weasel out of paying your claim.

author: wojtek077
author_rank: Contributor
timestamp: July 02, 2019, 01:52:39 am
content: Flasher saved my butt couple times on my other car. I got rear ended 4 times and blow couple red lights. People suck at driving in my area. Cops actually like the flasher but insurance wise you might have a point.

author: Monkeh
author_rank: Super Contributor
timestamp: July 02, 2019, 02:11:11 am
content: Quote from: wojtek077 on July 02, 2019, 01:52:39 amOne has to wonder about the common factor..

author: Gregg
author_rank: Super Contributor
timestamp: July 02, 2019, 02:24:55 am
content: It seems to me that the car is too smart for the flasher; i.e. the car module that switches the third brake light on when the vehicle is running thinks the there is a problem with the lamp but it bypasses its smart control when the key is off to still allow the third light to work for safety reasons.You may have to connect the wiring from the module to a resistor that satisfies the module’s criteria and connect the actual light to a separate (fused) source via a relay; most likely an opto isolated relay to keep any spikes from back feeding the module.Another possibility may be to find the output from the actual brake light switch but there is still the same risk of damaging the car’s expensive module.If you don’t want to roll your own opto isolated relay, here is a cheap module rated for 30 unrealistic amps but should be fine for your light.https://www.ebay.com/itm/1-Channel-Relay-Module-Board-With-Optocoupler-H-L-Level-Triger-30A-12V-24V/233255072799The combination high / low trigger allows these modules to easily isolate the LED trigger circuit from the power to the relay coil which can be on the same circuit as the relay output. They are also available in 10 amp rated, but for the small price increase I would go with the 30 amp rated.

author: james_s
author_rank: Super Contributor
timestamp: July 02, 2019, 02:43:30 am
content: Quote from: Monkeh on July 02, 2019, 02:11:11 amThat being what exactly? That people don't pay attention?I've been rear ended at least 8 times in the last 15 years, most minor, a couple hard enough to damage my car and one totaled it. In every case I was completely stopped either waiting at a red light or stopped in traffic when somebody who wasn't paying attention slammed into my back end. I'd love to know how that's my fault if that's what you're insinuating.People messing with their mobile phones while driving is an epidemic that now kills as many people as drunk driving. I ride the bus to work now and I see it multiple times every single day, people driving down the freeway looking down at a smartphone in their lap.

author: GregDunn
author_rank: Frequent Contributor
timestamp: July 02, 2019, 02:44:23 am
content: They are certainly not illegal in the US. In fact, many dealers will install them as aftermarket accessories when you purchase the car. There may be specific states which will not pass them during vehicle inspections, however that is a local ordinance.

author: james_s
author_rank: Super Contributor
timestamp: July 02, 2019, 02:48:11 am
content: I was going off of this when I looked into them:https://www.popularmechanics.com/cars/g1195/10-car-options-the-law-wont-let-you-have/I notice now it's several years old so maybe things have changed. I do advise consulting the laws in your state though as well as any states you may decide to drive in. I've been very tempted to get one as they do certainly grab my attention but having dealt with insurance adjusters before it makes me nervous.

author: wojtek077
author_rank: Contributor
timestamp: July 02, 2019, 05:01:36 am
content: Quote from: Gregg on July 02, 2019, 02:24:55 amI might do that keep it separate circuit or tap into the taillights. I was thinking doing as last option. Still might think over to either keep flasher you guys valid legal points.

author: SparkyFX
author_rank: Frequent Contributor
timestamp: July 02, 2019, 05:35:58 am
content: The output to the third brake light might be PWM controlled anyway.

author: Brumby
author_rank: Unknown
timestamp: July 02, 2019, 06:15:02 am
content: Quote from: james_s on July 02, 2019, 12:09:41 amI tend to agree. The flashing occurs at the beginning and then stays on. By the time someone startsactivelylookingat it, it is likely to be a steady light. Once they get to consciously realise that it's a brake light, then if it repeats the behaviour, it won't be so much of a surprise.QuoteThat's the point. Something that is changing in your field of view will get your attention. A single change like a light coming on might get missed if you blink - but flashing a few times is much more noticeable. Unless you notice a change, you might not see the light at all.A comparison situation is one that has happened to me once or twice whilst driving at night. I will be driving towards a set of traffic lights that are green and I may have glanced in my rear view mirror, across at another vehicle or some other potential hazard and when my eyes return to the road ahead, the lights have changed to amber in that fraction of a second. The amber traffic lights then disappear into the field of sodium vapour street lights and become one group. I then have to realise this before I can react. This doesn't take long - but itdoestake time. SEEING thechangefrom green to amber provides instant understanding.QuoteLegal requirements for vehicles, including lighting, are to ensure things perform to a minimum set standard. To have things certified as doing so requires some hoops to be jumped through and that can take time and money that only a serious local seller would bother doing if they wanted a marketing advantage. Correct me if I'm wrong - but the onus for legality doesn't lie with the person who sells such after market products, but with those who use it.One consequence can be that you may have a product that will exceed the required standards - but if it hasn't been granted formal certification, then you could be in for some trouble of one sort or another. Insurance adjusters are one potential source.

author: forrestc
author_rank: Unknown
timestamp: July 02, 2019, 06:25:53 am
content: Quote from: wojtek077 on July 01, 2019, 06:13:51 amHaving just dealt with a similar issue with replacing incandescent bulbs with LED's....Can you clarify what type of bulbs are in use in the third brake light. What type of car?If this is a modern car with LED's you might find that this isn't going to work since the body control module may include some LED driver circuitry in it.Have you measured across the third brake light when it is powered on (i.e. brake pedal depressed)? Is it 12V on and 0V off?

author: sokoloff
author_rank: Super Contributor
timestamp: July 02, 2019, 12:05:26 pm
content: Quote from: james_s on July 02, 2019, 02:43:30 amThat seemed interesting enough to poke for some data, so I went looking.It seems like distracted driving is about 30% as deadly as drunk driving in the US.NHTSA estimates 10,874 deaths in US from DUI in 2017NHTSA estimates 3,166 deaths in US from distracted driving in 2017

author: james_s
author_rank: Super Contributor
timestamp: July 02, 2019, 06:36:15 pm
content: Quote from: sokoloff on July 02, 2019, 12:05:26 pmInteresting, now I'm wondering what statistic I saw? Maybe it's the number of accidents rather than the number of deaths? Whatever the case it has reached epidemic levels and continues to increase. I see it every day, I've been the victim of it myself, I know plenty of other people who have been rear ended by someone who was texting or messing with their phone. It's such an easily preventable and entirely unnecessary thing too, just put the damn phone down and drive. If it's such a powerful addiction then put it in the glove box. It's reaching the point where I think it should be illegal to have a mobile phone within reach of the driver just like an open container of alcohol. Causing an accident due to distracted driving ought to be a criminal offense, fine of at least $10k, felony if it injures somebody. Maybe if getting caught messing with your phone while driving means a $600-$1200 ticket people will start to take a hint. I mean I see it myself numerous times every day and it's getting absurd. A while back some guy nearly mowed me down in a crosswalk as he rolled along staring down at the phone in his hand, he passed by about 2 feet away from me as I stared right at him and his eyes never came up until he had passed the crosswalk. I was wishing I had a shopping cart with me, I'd have let it go to roll in front of him.

author: wojtek077
author_rank: Contributor
timestamp: July 03, 2019, 07:40:38 am
content: Quote from: forrestc on July 02, 2019, 06:25:53 amLed 5 I think 2016 Focus stQuoteYeah that's problem but some people got it to work tho. In this video he's using the cheaper version of my module the s1. I contacted the seller he said that it's the same module but without the options for adjusting flashing and speed.https://youtu.be/4CWib_Ncu6QQuoteI think that's the problem goes down to 3v. I think module stays on and doesn't reset because of the 3v. Here's my video of my carhttps://youtu.be/Q9VJwAxUtEE

author: wojtek077
author_rank: Contributor
timestamp: July 03, 2019, 07:44:52 am
content: Quote from: SparkyFX on July 02, 2019, 05:35:58 amYeah it might be, I just don't have a oscilloscope to test it.

author: wojtek077
author_rank: Contributor
timestamp: July 03, 2019, 08:07:19 am
content: Uber and Lyft I hate to say but helped with drunk driving. DUI keeps getting more and more expansive which is a good thing. I got a feeling that cellphones the next new addition to the DUI. I was driving on the highway one night this girl going 70mph looking at her phone for good few seconds. My friend does road side assistance and his car's straight piped super load so he always goes next to car tell them to put phone down. He will speed up and slow down so kind he of forces them to put the phone down lol.

author: forrestc
author_rank: Unknown
timestamp: July 03, 2019, 01:21:17 pm
content: Quote from: wojtek077 on July 03, 2019, 07:40:38 amYou mentioned adding a resistor, where did you add it? Was it in series or parallel?One of my experiences in switching from incandescent to LED's was that the cruise control thought that the brake was always depressed because the LED's weren't pulling enough current to drop the voltage on the brake line down close to zero when the brake pedal was let up. I think it was also in the 3v range. It was cured with a load resistor across the 3rd brake light. I just used the same 6ohm 50W one everyone else uses (and is widely available on amazon). In your case, you may need to add this between the flasher and the rest of the car, however I'd be a bit concerned if the car came with LED brake lights already that you may end up drawing more than the car is expecting from that line and cause a longer-term fault.Another option would be to add a couple of 1N4001 or similar silicon diodes in series to try to drop a bit of the voltage. Each one should drop around 1 Volt. However this might affect the brightness of the brake light depending on the driver circuit in the light itself.

author: wojtek077
author_rank: Contributor
timestamp: July 03, 2019, 06:01:30 pm
content: QuoteYeah I added a 33ohms 1/2w resistor before the flasher and the led.QuoteI seen on back of led light saying 0.8w at 13.5v but drowning only 0.6w at 13.7v with a flasher too. I think I'm still good.QuoteI tried to add one 1n4001 but it same thing. I add them on positive side tho

author: james_s
author_rank: Super Contributor
timestamp: July 04, 2019, 02:02:22 am
content: Quote from: wojtek077 on July 03, 2019, 08:07:19 amIf I had a big ugly truck I'd be seriously tempted to pull a normally safe distance in front of them and brake aggressively. I'm not a fan of the typical approach to fighting drunk driving which is to just reduce the breath alcohol threshold that is considered drunk. I think that probably makes it worse, I mean if you're gonna get a DUI after one beer if you get caught anyway you might as well have a few more drinks, not gonna get in any more trouble. Instead I think they need to aggressively go after people who are heavily intoxicated and more so repeat offenders.A while back somebody around here drove right into the back of a DOT incident response truck that had flashing lights on, they were of course glued to their phone and didn't even look. Heck maybe if we stopped trying to make cars so safe it wouldn't encourage idiots to breed.

author: wojtek077
author_rank: Contributor
timestamp: July 04, 2019, 05:48:13 am
content: Yeah I agree, I don't even want a beer if I'm driving. People drive piss drunk and don't care. I keep road to a min tho you never know what people can do. And also have dashcam just in case.

author: forrestc
author_rank: Unknown
timestamp: July 04, 2019, 08:01:12 am
content: Quote from: wojtek077 on July 03, 2019, 06:01:30 pmMy suggestion was to draw around 25W on the brake light circuit to force the voltage when off to drop to zero. i.e. put a 6ohm resistor in parallel with the entire thing.If the existing one is only drawing 1W this would be too much.You could also try a 3.3V zener backwards so that it adds 3.3V of drop.Edit/Addition: It also occured to me just after I posted this reply that there are circuits out there which will cut off below a certain voltage. Usually they're used to prevent overdischarging a rechargeable battery or prevent something from running at too low of a voltage. If you google 'low voltage cut off circuit' or 'low voltage disconnect circuit' you'll probably find a few.

author: SparkyFX
author_rank: Frequent Contributor
timestamp: July 04, 2019, 09:14:00 am
content: Quote from: wojtek077 on July 03, 2019, 07:44:52 amCheck the voltage with a multimeter while on, it gives you a different mean value when it´s not DC.

author: wojtek077
author_rank: Contributor
timestamp: August 14, 2019, 06:07:26 am
content: Quote from: forrestc on July 04, 2019, 08:01:12 amSorry late reply but what zener would use I'm getting overwhelmed with data sheets and how would wire it up towards the ground or positive side.QuoteI been looking but I couldn't find one. I found relay ones but I don't trust those. I wonder if there will be a delay with the zener?

author: wojtek077
author_rank: Contributor
timestamp: August 14, 2019, 06:18:22 am
content: Something like this

author: forrestc
author_rank: Unknown
timestamp: August 14, 2019, 06:52:09 am
content: See section 3 about a voltage shifter at this page:https://circuitdigest.com/tutorial/zener-diode-types-applications-and-operational-principleThe resistor probably isn't needed in your application since your device will stand in as the resistor.You choose the zener based on the amount of voltage drop you need. You'll also need to size it big enough current-wise and power-rating wise so that the amount of current you're passing through the zener doesn't result in the zener overheating.

author: ledtester
author_rank: Super Contributor
timestamp: August 14, 2019, 09:49:54 am
content: fwiw, here is, I believe, the first patent granted for a flashing brake light: #3,460,089 granted in 1969:https://patentimages.storage.googleapis.com/62/e6/3a/432bbdfbb55446/US3460089.pdfIt is interesting to read how it works. No 555 timers or even any solid state electronics here:Quote

author: james_s
author_rank: Super Contributor
timestamp: August 14, 2019, 03:51:33 pm
content: That sounds an awful lot like the ordinary thermal flashers that have been around for decades. It wasn't until the 80s that I started seeing electronic flashers used for turn signals.I remember you could get thermal button flashers that stick on the end of a lightbulb base. They worked well at first but eventually the bulb would heat up and the flashing would get feeble, only blinking off very briefly.

author: wojtek077
author_rank: Contributor
timestamp: August 14, 2019, 06:59:52 pm
content: Quote from: forrestc on August 14, 2019, 06:52:09 amOn voltage fine but when I release brake pedal there's still leakage. Can I put the zener backwards and do a low voltage cut off?

author: wojtek077
author_rank: Contributor
timestamp: August 14, 2019, 07:18:41 pm
content: Quote from: ledtester on August 14, 2019, 09:49:54 amWow 1969

author: james_s
author_rank: Super Contributor
timestamp: August 14, 2019, 08:48:38 pm
content: I'm not sure why that is surprising, turn signals had thermal flashers at least as far back as the 1930s. By 1969 solid state flashers were possible, I mean we had computers, transistor radios, jet airliners and moon rockets by then.