[Loki223]

You need to put in a diode so that the power from the run signals can't back track through the brake line, having them wired together is fine, but you need a diode there

These should work great for you

Amazon.com: Hopkins 48955 Towed Vehicle Diodes Kit : Automotive

Buy Hopkins 48955 Towed Vehicle Diodes Kit: Wiring - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[Rollers999]

You need to put in a diode so that the power from the run signals can't back track through the brake line, having them wired together is fine, but you need a diode there

These should work great for you

Amazon.com: Hopkins 48955 Towed Vehicle Diodes Kit : Automotive

Buy Hopkins 48955 Towed Vehicle Diodes Kit: Wiring - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

So the link you provided shows two input one output diodes. Can both turn signal and brake be the inputs with one output and everything still work correctly?

With a 50w 6ohm resistor in parallel with the lights now I’m still showing a light out on the dash. Have yet to figure that out.

 

[Loki223]

On the first part yes. It'll run perfectly

On the second what year is your truck?

 

[Rollers999]

On the first part yes. It'll run perfectly

On the second what year is your truck?

Well that’s a plus!

2005.

 

[Loki223]

Ah yes, 05....the ******* year. Makes me miss my old 05. And not miss it at the same time. So lets do this one step at a time. First step, get your lights working correctly. Once you have the diodes installed, we can tackle the light out notification. For now though, is the light out notification for the brake light, running light, or turn signal? Do you have hyper flash? And where do you have the resistors wired in? On both sides turn and stop, or just one side stop and both turn? or??

 

[Rollers999]

Ah yes, 05....the *** year. Makes me miss my old 05. And not miss it at the same time. So lets do this one step at a time. First step, get your lights working correctly. Once you have the diodes installed, we can tackle the light out notification. For now though, is the light out notification for the brake light, running light, or turn signal? Do you have hyper flash? And where do you have the resistors wired in? On both sides turn and stop, or just one side stop and both turn? or??

It's definitely love/hate relationship with this truck. I couldn't let it go though. Well the diodes have been ordered, when they do come in I will get them wired up. I plan on putting the brake on one input and the turn signal on the other while having one output to the lights. The notification is on everything at the moment, press the brake it comes on, use signal it comes on. Running lights is just fine when I turn them on no indicators on the dash. At the moment I have one 50w 6ohm resistor wired in parallel after both have been tied in together and grounded to the frame. I'm going to take a wild guess I need to put them upstream separately on each incoming power (both brake and turn signal) for it to work correctly.

 

[Loki223]

Well once you have the diode in, we can work on the rest of it. The diodes are basically backflow preventers, only allows the electricity to travel one way, with that in mind you might be able to use one resister after the diode, but it could be necessary for each wire to have a resistor. I'd wonder if @steve05ram360 might know more on the 3rd gen wiring to help out with the load resistors as i know the 3rd gens are finicky to put it lightly. @krashDH might have some good input as well

 

[krashDH]

I did a writeup on how to defeat hyper flash and the bulb out signal for our tail lights when using LEDs. I built custom harnesses, but you don't have to get this fancy...

3rd Gen, LED Tail Lights, Write-Up

Well I figured I'd post a complete thread if you're wanting to run LED tail lights without any errors. I searched this forum as well as others for a detailed write-up and found bits and pieces, but nothing complete. So here we go. As is very well documented, our trucks are very picky with the...

www.cumminsforum.com

 

[Rollers999]

Well once you have the diode in, we can work on the rest of it. The diodes are basically backflow preventers, only allows the electricity to travel one way, with that in mind you might be able to use one resister after the diode, but it could be necessary for each wire to have a resistor. I'd wonder if @steve05ram360 might know more on the 3rd gen wiring to help out with the load resistors as i know the 3rd gens are finicky to put it lightly. @krashDH might have some good input as well

I’ll have to do some more digging on placement and if I’ll need two or not. When I get the diodes in I’ll plan to have a spot for the resistors when I’m in there as well. I go back into work for four nights so it’ll be early next week before I can continue on this.

 

[Rollers999]

I did a writeup on how to defeat hyper flash and the bulb out signal for our tail lights when using LEDs. I built custom harnesses, but you don't have to get this fancy...

3rd Gen, LED Tail Lights, Write-Up

Well I figured I'd post a complete thread if you're wanting to run LED tail lights without any errors. I searched this forum as well as others for a detailed write-up and found bits and pieces, but nothing complete. So here we go. As is very well documented, our trucks are very picky with the...

www.cumminsforum.com

I just was looking at your write up. Very detailed and I like what you did. I have already tapped into the factory harness. Wasn’t to concerned about tapping into it as I saved the connectors in case anything ever changes which is highly unlikely.

How you have your resistors wired is pretty much what I have except there is only one in line with both turn signal and brake combined. Sounds like I need to have two, one for each and we should be golden.. I hope.

 

[krashDH]

I just was looking at your write up. Very detailed and I like what you did. I have already tapped into the factory harness. Wasn’t to concerned about tapping into it as I saved the connectors in case anything ever changes which is highly unlikely.

How you have your resistors wired is pretty much what I have except there is only one in line with both turn signal and brake combined. Sounds like I need to have two, one for each and we should be golden.. I hope.

You need one in parallel with the signal and one in parallel the brake line per side.
4 total. Signal resistor prevents hyperflash/bulb out, brake bulb resistor prevents bulb out warning.

 

[Rollers999]

You need one in parallel with the signal and one in parallel the brake line per side.
4 total. Signal resistor prevents hyperflash/bulb out, brake bulb resistor prevents bulb out warning.

Makes total sense. Now I wonder if I can tie brake and turn signal together after the resistors to keep both lights functioning or if they would have to be separate. Wonder if it would also decrease the need for diodes.

 

[krashDH]

Makes total sense. Now I wonder if I can tie brake and turn signal together after the resistors to keep both lights functioning or if they would have to be separate. Wonder if it would also decrease the need for diodes.

Resistors don't prevent backfeed, diodes do that as mentioned.

Depends on how you wired what you're going for.

 

[Rollers999]

Resistors don't prevent backfeed, diodes do that as mentioned.

Depends on how you wired what you're going for.

Correct. Plan is to have both turn and brake incoming the same diode and having one output to both leds with resistors before the diode. Hopefully it works as well as I should intend.

 

[Rollers999]

Update: Wired in resistors for both brake and turn signals. The light out indicator on the dash went out. But flashes twice when I turn the running lights on and the turn signal starts blinking fast again. Not sure what the problem is there. Wired in diodes as well (which are easily removable) with no fix on the bleeding over to the other side or other rear running lights. After just digging around and pondering I took a 10amp fuse (first one I grabbed) and shorted out one of the rear marker lights that aren't even in the turn signal/brake circuit and it fixed the issue. So that tells me there still isn't enough load on the actual lights to make them function correctly without bleeding over or do I have another issue I'm not seeing?

Update #2:
So pulled the diodes out of the mix and the light out indicator comes back on. Pulled the quick connects going to the lights with just the resistors in line and the indicator light goes away. Not so sure whats going on here.

Also noticed one brand of rear markers 2" lights (5 out of the 9) don't flash when the turn signals are on but the other off brand ones do. I thought this might be a light issue along with the actual 6" tails. Went and got 4 new 6" tails and that didn't seem to fix the problem.

There is so much going on here I'm not sure where to look next or what to even do.

 

[krashDH]

Post a schematic of your wiring

 

[Rollers999]

Post a schematic of your wiring

Turn signal and brake have their own resistors, each have their own diodes. All lights have the same common ground daisy chained.

When running lights are off everything works as it should besides the bleeding over so to speak but it’s faint not as bright as the actual signal that’s flashing. Again if I jump one of the rear marker lights with a fuse it goes away. Also not all of the 2” marker lights flash it’s a select few that do and their a different brand and also look different. Not sure if there is something going on there.

When the running lights are on and you use a turn signal the bleed over stops but also flashes quickly like a light is out.

Here is a little schematic.