LED tail light woes!

Flameffects

Observer
Ok I have a 2001 FUSO FG. I installed LED turn signals on my truck bed. Of course I got the hyper flash. I then installed 50w 6 ohm resister and I still have a hyper flash. I doubled the resistance and got the same hyper flash. When I use the four ways I get a slow or normal flash. Anyone have a fix or ideas?
 

pugslyyy

Expedition Vehicle Engineer Guy
Ok I have a 2001 FUSO FG. I installed LED turn signals on my truck bed. Of course I got the hyper flash. I then installed 50w 6 ohm resister and I still have a hyper flash. I doubled the resistance and got the same hyper flash. When I use the four ways I get a slow or normal flash. Anyone have a fix or ideas?
I've just been living with the fast flash.
 

gait

Explorer
just a thought ... is you vehicle 12v or 24v

6 ohm at 12v is about 24w which is about equivalent to 21w incandescent flasher (indicator) bulb. If vehicle 24v and bulb 21w then double resistance "should" work.

Have you tried one of the old incandescent bulbs in parallel without the resistance?.

Are you sure all the earth connections are good?
 

pugslyyy

Expedition Vehicle Engineer Guy
Ok I have a 2001 FUSO FG. I installed LED turn signals on my truck bed. Of course I got the hyper flash. I then installed 50w 6 ohm resister and I still have a hyper flash. I doubled the resistance and got the same hyper flash. When I use the four ways I get a slow or normal flash. Anyone have a fix or ideas?
the resistor needs to be in parallel with the LED not in series with it.
 

gait

Explorer
PS check continuity of resistors. If they've been at 24v may be cooked as it exceeds spec by about 2x.

I need to check my maths. 24v needs 24 ohm for 24 watt. ie 4 of those resistors in series. Hence, try old bulb in parallel with leds.
 

Flameffects

Observer
Get rid of the resistors and replace the flasher with an electronic one that supports LEDs.
None seem to be available for this vehicle. Or none that I can find. The relay is masive and has a large pin connector with at least 8 wires. I was hopping someone was making an aftermarket unit.
 

Flameffects

Observer
just a thought ... is you vehicle 12v or 24v

6 ohm at 12v is about 24w which is about equivalent to 21w incandescent flasher (indicator) bulb. If vehicle 24v and bulb 21w then double resistance "should" work
Are you sure all the earth connections are good?
Have you tried one of the old incandescent bulbs in parallel without the resistance?.

The vehicle is 12V. The earth ground connections a good. Old bulb works and slows flasher.
 

SkiFreak

Crazy Person
When I made my rear bar I used LED lamps and did not have any issues, but when I changed the indicators in the bullbar from incandescent to LED I got the dreaded super fast blinking.
I guess that by adding the front indicators I went below the resistance that the ECU would accept. To fix the problem I simply used commercial LED load resistors that were wired in parallel with each indicator's power and earth wire.

As mentioned earlier, fitting an electronic relay is the best solution as using load resistors negates any power saving benefit of fitting LED lights but, if like me you fitted LED lights because they are normally more reliable, then it is not as much of an issue.

load_resistor_01.jpg

I should add that on some of the newer trucks (the FGB-71 as an example) it can be a real pain to replace incandescent bulbs with LEDs. Just ask the guys at ATW how much fun they have had doing this. From what I was told, there were some circuits where it was considered "just too hard". Whatcharterboat would be able to tell you all about that.
 

Flameffects

Observer
When I made my rear bar I used LED lamps and did not have any issues, but when I changed the indicators in the bullbar from incandescent to LED I got the dreaded super fast blinking.
I guess that by adding the front indicators I went below the resistance that the ECU would accept. To fix the problem I simply used commercial LED load resistors that were wired in parallel with each indicator's power and earth wire.

As mentioned earlier, fitting an electronic relay is the best solution as using load resistors negates any power saving benefit of fitting LED lights but, if like me you fitted LED lights because they are normally more reliable, then it is not as much of an issue.

View attachment 309974

I should add that on some of the newer trucks (the FGB-71 as an example) it can be a real pain to replace incandescent bulbs with LEDs. Just ask the guys at ATW how much fun they have had doing this. From what I was told, there were some circuits where it was considered "just too hard". Whatcharterboat would be able to tell you all about that.
As mentioned in my opening statement I have installed above mentioned resistors….well not exactly they are 12 volt 50W 6ohm resistors. I have tested them on the bench, installed them parallel and in series without success……I guess I am over it.
 

SkiFreak

Crazy Person
It is very strange that when you have included a bulb it woks but it does not with the resistor. There is not logic to that at all, as they are basically the same thing.
The only thing I can think of is that you have too much resistance when using the 50W resistor and the sysem is also seeing that as a "fault". As I understand it, the resistor needs to match the wattage of the bulb being replaced.
Have you tried one of these commercial resistors? I did not pay that much for two of them and they definitely fixed the problem for me.
 

Flameffects

Observer
It is very strange that when you have included a bulb it woks but it does not with the resistor. There is not logic to that at all, as they are basically the same thing.
The only thing I can think of is that you have too much resistance when using the 50W resistor and the sysem is also seeing that as a "fault". As I understand it, the resistor needs to match the wattage of the bulb being replaced.
Have you tried one of these commercial resistors? I did not pay that much for two of them and they definitely fixed the problem for me.
In my manic obsessive madness I managed to find a note in the manual that mentioned just what you are suggesting…..two may watts. I just place an order for 25 watt pair. Hope this works!
 

pugslyyy

Expedition Vehicle Engineer Guy
...there has to be some issue with the install. a 6 ohm 50W resistor in parallel with the LED will work. either it wasn't installed parallel to the LED or the resistor is bad (or the wires soldered to it)


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