I had to replace a tail light housing when a bulb holder went bad - open circuit. When the replacement housing quickly went bad (same problem), I found a set of LED taillights I could afford. Now I have a hyper-flash problem.
When I originally searched the web about the problem, I found a circuit diagram that showed a sampling resister in series with the bulb, with a connection to a terminal on the flash controller across the flasher chip.Got out my slide rule and determined that I could replace that particular resister with about a .6 ohm resistor. Also found more instructions telling where the resistor was located, and that it could be replaced reasonably quickly. Seems to me that location was near the base of the steering column. Some consideration suggests it might be actually located in or near the turn signal switch since a quick look over didn’t show any promising housings near the floorboard.
I never bookmarked the references, and can no longer find them with a google search. However, I did find that I could put a couple of 6 ohm resistors in parallel with the led bulbs across appropriate wires in the wiring in the taillight bezel to draw enough extra current to fool the flash controller.
Prefer to try the steering column fix. Please point me in the right direction.
What you are saying should work, but it seems like it defeats the purpose of using LED tail lights. But ignoring that for the moment, I have no idea how much current an incandescent tail light bulb uses. But I could come up with a guess I think. Here goes.
Think about a small desk lamp, a 35 watt light bulb, how bright that is. How bright it a tail light bulb compared to that? Maybe 1/4 as bright? Ok, so a tail light bulb is a 10 watts then. The current for a 10 watt bulb is derived from the eqn: Power = current * voltage. So current = Power/voltage. So a 10 watt bulb would use 10 watts/12 volts or about 1 amp.
So what you need for each tail-light bulb is to draw about 1 amp, assuming the LED draw was much lower than 1 amp. So how much resistance is needed for a 1 amp draw? That is derived from the eqn: Current = voltage/resistance. So resistance = voltage/current. So for a 1 amp draw the resistor would be 12 volts/1 amp, or 12 ohms.
So I think you could use 12 ohm* rather than 6 ohm resistors. If you could post a wring diagram the experts here might could come up w/a good placement not in the tail lights. But it seems like it would be easier to just put the resistors in the tail light fixtures. Is there a reason you prefer not to do that? Involving the steering column only adds a complication to the process.
Edit: Note that the resistors would have to be rated 10 watt, preferably a little higher.
Have you tried turning the LED lamp around? LEDs are polarity sensitive, and if the bulb is backwards it’ll act like a bulb is blown and you’ll get hyperflashing.
Something doesn’t make sense to me…IF this vehicle has a sense resistor for controlling the flash rate, it should also automatically compensate for changes in the voltage drop across the sense resistor, otherwise, why have it? I don’t believe that is its purpose. It’s more likely being used to sense if the lamps are burned out or not to illuminate a check bulbs annunciator. If that’s the case, changing the value will have no effect on the flash rate.
LEDs are diodes. If you put them in backwards, they block current flow and do not flash unless you exceed the breakdown voltage (zener) which is significantly higher than the car’s bus voltage…
It’s likely that the LED lamps aren’t drawing nearly as much current as the original incandescent bulbs and this is fooling the flasher module (which is electronic and contains a microprocessor) into thinking you have a lamp out. These modules are programmed to act like an old bi-metal flasher and blink fast if a lamp is out. You should be able to add some resistance in series with the bulb–not sure if it will make it dimmer or not. It might be worth contacting the vendor and seeing if they have a solution. I have no idea if this will work, but you can try measuring the resistance of the original bulb with an ohmmeter and trying to add a similar resistor in series with the LED lamp. This will likely need to be a pretty heavy-duty resistor, probably a wire-wound or it will burn up. The problem with doing this is after an incandescent bulb’s filament heats up, the resistance changes, so not sure what the final value will be compared to the ‘cold’ value you’d test with an ohmmeter.
Probably db4690’s suggestion is best if you can find one.
However, I did find that I could put a couple of 6 ohm resistors in parallel with the led bulbs across appropriate wires in the wiring in the taillight bezel to draw enough extra current to fool the flash controller.
This is the easiest fix. BUT, remember that these resistors will be putting out 27 watts of heat, so make sure they’re not touching plastic. (Really, you’re better off using stock bulbs.)