LED turn signal bulbs need resistor. Any way to do it cheap?

[BK]

So uh, was the consensus that an EP-27 will fix the fast flash? I have rear LEDs, front incandescents. My trailer also goes off of my truck wiring and has about 50 feet of 18 ga wire with LED flashers. It still flashes fast with the trailer hooked up.

I assume it flashes quicker with the trailer hooked up?



I'm using that Tridon makes electronic flashers, and it worked for me.

Any true electronic flasher, ( it has an electronic timing ckt and drives a relay) will solve the problem of the fast flashers...

 

[PatrickCampbell]

No it doesn't flash more quickly with the trailer hooked up. Not that I can tell. Why would it?



Ideally I would like it to flash at the proper speed with both the trailer on and off. I will check out this EP-27.

 

[BK]

No it doesn't flash more quickly with the trailer hooked up. Not that I can tell. Why would it?



Ideally I would like it to flash at the proper speed with both the trailer on and off. I will check out this EP-27.

The additional load of the trailer lights will cause the metal contacts to heat up quicker and cycle quicker.



The stock flashers rely on the heating of bi-metal contacts, from the current draw of the lights. The less lights or lower the current draw, the slower they will flash, more the current draw or load, the quicker.



But it just might be soo quick now that the trailer doesn't matter.





The resistor that kicked this off, was made to use with a bi-metal flasher that flashed too slow, so by adding the resistor like another light, it increased the load and would speed up the flashing to something more normal.



But I have to say the electronic flasher is the way to go.

 

[PatrickCampbell]

I'll check out the electronic flasher ... seems like the way to go.



But... If you are saying the stock flashers should flash slower with less draw, why does it flash fast when you change the stock bulbs to LEDs. LEDs use much less current than incandescent bulbs.

 

[Thomas]

So uh, was the consensus that an EP-27 will fix the fast flash? I have rear LEDs, front incandescents...

I'm having trouble following this thread since it started with second-generation 12-valve Rams and changed to second-generation 24-valve Rams (different turn signal/emergency flasher wiring).

The EP27 (second-generation 24-valve Rams) originally did not work with LED's. TDR member Shelby Griggs got the ball rolling so that Trico/Tridon changed the EP27 to work with both incandescent and LED lighting - check his posts in these three threads:


https://www.turbodieselregister.com/forums/showthread.php?t=33458

https://www.turbodieselregister.com/forums/showthread.php?t=36595

https://www.turbodieselregister.com/forums/showthread.php?t=64808

 

[BK]

A turn signal or hazards, on any year or make all run off of the same flasher.

US or import, Dodge or Fd, it's all the same problem.



To lightly loaded, they take a very long time to flash.

To heavily loaded, they flash to quick.



Adding a resistive load will solve the flasher flashing too slow from too light of a load from changing over to all LED. To Low of a current draw from the lights and the old bi-metal flashers heat up too slow.



Going to an electronic flasher will solve them flashing too quick or too slow.

Any make/model/year/Gen.

 

[PatrickCampbell]

BK still does not explain why switching to LEDs makes it flash fast. By your statement switching to LEDs should make it flash slowly. LEDs use very little current.

 

[draymorris]

I agree - LED's draw less current - should make the flasher flash slower or not at all. Since I was on this thread last, I have called a manager at the truck stop where I bought these (Danny's big rig resort - Phoenix, AZ). He said that this happens on many of the big trucks that they install LED's and yes it needs a resistor- they carry them for that purpose. I told him that it did not make since that the lights would flash faster - he agreed that it did not make sense, but that is what they do. He told me that they could put a reisistor in, in about 5 minutes. We talked about this for a bit, so I am sure he understood what I was saying.



To furthur confuse things--

I am talking about a 06 dodge - all electronic. I beleive the rest of this thread may be on 2nd and 1st gen? The service mgr at my dealer, told me that there is no flasher on my truck and that it is done electronically - anyone disagree? Please tell me where to find the flasher if you do disagree.



Next, it is true that LED's draw less current - so why would it flash faster related to more draw. I personally know a man who intalled LED's on his flatbed, and his singnal would not work - they would flash once and then no more - I left one bulb in the circuit and that made it work. ???!!!???

I guess on mine I will try the resistor and see what happens, but I don't see how this will work any different - I currently still have 2 incandescent bulbs on the headache rack and the front bulbs in the circuit.



As for the trialer lights effecting the flashing - are not the trailer circuits isolated from the truck - the fuses in my fuse block are trialer specific - I think.

 

[Thomas]

A turn signal or hazards, on any year or make all run off of the same flasher...

Twelve-valve Rams have two flashers - one for the turn indicators and one for the hazards.

... Going to an electronic flasher will solve them flashing too quick or too slow.
Any make/model/year/Gen.

The service manuals for the ISB equipped Rams describe the combination turn signal/hazard warning flasher as a SMART relay. The flasher has the footprint of an ISO type relay but the internal circuitry is much different. It also contains active electronic Integrated Circuitry elements. In operation, the flasher is designed to handle factory-installed lighting current flows. If extra lighting-as in towed vehicle-is added, the flasher automatically tries to keep the flash rate the same. When the unit detects missing or blown bulbs it triggers a rapid flash rate.

This OEM flasher that came with the ISB will flash at a rapid rate if significantly less than the expected load is seen on any lamp circuit, whether caused by a blown filament, socket problem, missing bulb, or LED's installed in place of the bulb.

Instead of "Going to an electronic flasher will solve them flashing too quick or too slow. Any make/model/year/Gen. " , this is a case of the electronic flasher causing the rapid flash.

 

[draymorris]

I agree - LED's draw less current - should make the flasher flash slower or not at all. Since I was on this thread last, I have called a manager at the truck stop where I bought these (Danny's big rig resort - Phoenix, AZ). He said that this happens on many of the big trucks that they install LED's and yes it needs a resistor- they carry them for that purpose. I told him that it did not make since that the lights would flash faster - he agreed that it did not make sense, but that is what they do. He told me that they could put a reisistor in, in about 5 minutes. We talked about this for a bit, so I am sure he understood what I was saying.



To furthur confuse things--

I am talking about a 06 dodge - all electronic. I beleive the rest of this thread may be on 2nd and 1st gen? The service mgr at my dealer, told me that there is no flasher on my truck and that it is done electronically - anyone disagree? Please tell me where to find the flasher if you do disagree.



Next, it is true that LED's draw less current - so why would it flash faster related to more draw. I personally know a man who intalled LED's on his flatbed, and his singnal would not work - they would flash once and then no more - I left one bulb in the circuit and that made it work. ???!!!???

I guess on mine I will try the resistor and see what happens, but I don't see how this will work any different - I currently still have 2 incandescent bulbs on the headache rack and the front bulbs in the circuit.



As for the trialer lights effecting the flashing - are not the trailer circuits isolated from the truck - the fuses in my fuse block are trialer specific - I think.

 

[Joe G.]

If the electronic flasher is controlled by timing and not current flow then the load on the circuit is irrelevant. If it is designed to warn if there is something wrong it may quick flash, but that is designed in rather than being a direct affect of current flow.

 

[BK]

I'll check out the electronic flasher ... seems like the way to go.



But... If you are saying the stock flashers should flash slower with less draw, why does it flash fast when you change the stock bulbs to LEDs. LEDs use much less current than incandescent bulbs.

Sorry Pat, I had missed that point.

But never fear, make some stead fast general statements and others quickly pipe in with the answer !! Works every time.



Seriously I did not know the 12V had gone to two flashers, and had tried to improve on them. Mine only has one, 24V 99. That's the first I've hear if it.



And this is the first I heard about the 06's integrating the flashers into the body computer or where every they may have stuck this function.

 

[Thomas]

... And this is the first I heard about the 06's integrating the flashers into the body computer or where every they may have stuck this function.

The traditional mechanical & electronic flashers ceased to exist as discrete items beginning with third-generation Rams. From the 2002 Ram 1500 (third-generation) Factory Service Manual:

The turn signal indicators give an indication to the​

vehicle operator that the turn signal (left or right
indicator flashing) or hazard warning (both left and
right indicators flashing) have been selected and are
operating. These indicators are controlled by transistors
on the instrument cluster electronic circuit board
based upon the cluster programming, a hard wired
multiplex input received by the cluster from the turn
signal and hazard warning switch circuitry of the
multi-function switch on the turn/hazard switch mux
circuit, and electronic messages received from the
Front Control Module (FCM) over the Programmable
Communications Interface (PCI) data bus. Each turn
signal indicator Light Emitting Diode (LED) is completely
controlled by the instrument cluster logic circuit,
and that logic will allow this indicator to
operate whenever the instrument cluster receives a
battery current input on the fused B(+) circuit...

 

[BK]

The traditional mechanical & electronic flashers ceased to exist as discrete items beginning with third-generation Rams. From the 2002 Ram 1500 (third-generation) Factory Service Manual:

The turn signal indicators give an indication to the​

vehicle operator that the turn signal (left or right

indicator flashing) or hazard warning (both left and

right indicators flashing) have been selected and are

operating. These indicators are controlled by transistors

on the instrument cluster electronic circuit board

based upon the cluster programming, a hard wired

multiplex input received by the cluster from the turn

signal and hazard warning switch circuitry of the

multi-function switch on the turn/hazard switch mux

circuit, and electronic messages received from the

Front Control Module (FCM) over the Programmable

Communications Interface (PCI) data bus. Each turn

signal indicator Light Emitting Diode (LED) is completely

controlled by the instrument cluster logic circuit,

and that logic will allow this indicator to

operate whenever the instrument cluster receives a

battery current input on the fused B(+) circuit...

Haven't read that book yet (LOL), nor worked on anything out of the 2nd gen.

That's really a peice of work. If you have a wiring issue, a mistake is made with wiring trailer lighting and the sensing and driver ckts take a hit, it's a cluster assy and possibly a cascading failure into the FCM. Geez. . talk about an expenisive wiring mistake.



Are they atleast using external inline blocking and clamping diodes and fusing to protect the the whole lot? And can be replaced with out replacing the whole lot?



More reasons to stay with the 2nd gen. Less integration = more foregiving.

 

[PatrickCampbell]

Well. At this point I am saying who cares. I got the EP27 and problem is solved. FWIW, the truck is an 01. 5. The rear blinkers are LED. The fronts are stock. Blinking is a little slower than stock... more like a Buick or something. Better than spastic!

 

[starkmr]

FYI the resistors you were looking at the radio shack that were 5 for a dollar, were most likely no more than 1/2 watt resistors. The kit called for 6 ohm 50 watt resistors which I would think you would have a hard time finding at RS. The 1/2 watt resistors will burn out fairly quickly in this application.

 

[BK]

FYI the resistors you were looking at the radio shack that were 5 for a dollar, were most likely no more than 1/2 watt resistors. The kit called for 6 ohm 50 watt resistors which I would think you would have a hard time finding at RS. The 1/2 watt resistors will burn out fairly quickly in this application.

Just so folks don't go buying 1/2 watts and wondering way they turn black... . and let out all the magic electrical smoke that makes it work.



Ohms law says: 13. 8V/6 ohms = 2. 3A x 13. 8V = 31. 74Watts!



It's a load resistor meant to load down the bimetalic flasher... or current sensing ckts in the newer trucks.

It's not a current limiting resistor for the LEDS. .

If it were you'd be right, @ 10ma only need about . 113watts , so a 1/2 w would be great. . but that's for only 1 LED.

 

[willysrule]

When I put all LED lights in my jeep (two 4" for front signals and two 4" rears) I had the same problem... I bought a few cheap trailer lights and used the bulb and socket. If you wire a bulb and socket onto the one lead to the LEDs it will help with the draw needed for the flasher to work... I wired one at each corner and tucked the bulbs out of the way... it's worked flawlessly for 4 years...

 

[starkmr]

BK

You got it right, I just didn't feel like breaking out the math!!!!



Willysrule

You did basically the same thing only you are using the light bulbs resistance as your load. The 6 ohm, 50 watt resistor does the same thing without burning a light. Your solution will go haywire when the bulbs burn out as this load will not be present any longer. Simple solution is to replace the bulb as you did before.



Personally, I would spend the bucks somewhere besides Radio Shack. Look for an electronics component store in your area. The needed resistors should not cost $10 per unit, this is just manufacturer mark up.



Just my . 02

 

[SHobbs]

Would be nice if we 2nd genners could get the L. E. D replacements for the O. E. M's like the 3rd gens. A member here posted pics of a set and JC Whitney has them as well. Instead of replacing the bulb the whole assembly is replaced.