Replaced Running Lights With LEDs

VN Warrior1966 · 07-09-2018, 02:55 PM

I replaced my all running lights with LEDs last year on my 2015 Signature UL 8315BSS TT and everything was fine while towing it with my former truck, a 2014 F-150. But now that I have a 2018 F-150, I keep getting disturbing messages on the truck's info screen; such as "Right (and Left) Brake Light Fault" and "Trailer Disconnected." I checked the lights and everything was functioning as required however, the disturbing messages continued. I have had the new F-150 back to the dealer four times and they have tested, retested, and replaced a module (due to a similar problem manifested in a different model vehicle) and yet, the problem remains. I have even replaced the 7-pin connector from my TT just to ensure a solid connection (and yes, I used Dielectric grease just to be sure this time around). Anyone else ever have this problem? Any suggestions as to how to solve this dilemma? Many thanks in advance.

5picker · 07-09-2018, 03:01 PM

Many trucks are monitoring current draw in the circuitry via the body modules to keep a watch for burned out bulbs so they can display a warning.

Since LED bulbs use way less current, often times they will flag the module of problems when there really isn't one.

The only way to know for sure is change the bulbs back and see if the issue goes away.
I know that isn't what you want to hear but you'll likely know for sure by doing so.

Nathan 18 · 07-09-2018, 10:02 PM

Some auto LED bulbs have built in resisters to compensate for the low current draw of LED's. Others have added a resistor to LED bulb circuits to deal with the issue you have described

dbledan · 07-09-2018, 10:21 PM

The F150s are looking at load on the circuit to know if there is a problem as others have said.

I left one of my marker lights as incandescent bulbs and it worked for that. If you want all LEDs and the bulbs do not compensate for the smaller load you need to get a load resistor like this. https://www.superbrightleds.com/more...g-fix/191/832/ it will wire into the fixture and should resolve your problem I think.

You may need 3. 1 for running lights, one for left brake/turn, one for right brake/turn if everything is LED and does not conpensate for the difference.

I will also say that I had similar issues and I found that not bottoming out the 7pin connector makes it work better as well even with the dielectric grease.

Hope that helps. Best of luck!

18CrewDually · 07-09-2018, 10:33 PM

Contact your dealer and tell them you switched the bulbs to LED. Using Ford's IDS (Integrated Diagnostic Software) they can go into the parameters of the BCM (body control module) and change them so it will not detect it as a blown bulb.
You can do it yourself with Forscan and a laptop but it requires the Forscan software, and the process may be baffling, to say the least, for the non-tech folks.

Larry-NC · 07-10-2018, 02:15 PM

Quote:

Originally Posted by Nathan 18

Some auto LED bulbs have built in resisters to compensate for the low current draw of LED's. Others have added a resistor to LED bulb circuits to deal with the issue you have described

Yes, these are referred to as "CAN-bus compatible" since the digital data bus that polls the light socket and reports undercurrent is called the CAN bus. It stands for Controller Area Network bus.

These LEDs consume just as much current as the incandescent lamps they replace. Their only benefit is a longer lifetime.

Larry

67L48 · 07-10-2018, 03:40 PM

FORscan is a program that lets you interface with the settings/config of your Ford. No warranty implications here, as you're not interfacing with the ECM or affecting any of the operation of the drivetrain. This is just doing things like turning off seatbelt chimes, adding heated seat button icons to your display, and other things. Ford wrote all the code to turn things on and off, you're just accessing these configurations. It would save you a trip to the dealership if you needed to change something regarding LED bulbs.

Good luck.

Jay2504 · 07-11-2018, 07:16 PM

Is there a FORscan for chevys? Jay

**Flybob** · 07-11-2018, 07:27 PM

You can purchase LED resistor kits on Amazon. Much easier than modding software.

VN Warrior1966 · 07-15-2018, 07:23 AM

Thanks for all the info! I greatly appreciate your suggestions and your time.

18CrewDually · 07-16-2018, 12:18 AM

Quote:

Originally Posted by Jay2504

Is there a FORscan for chevys? Jay

For(d)Scan is for Ford only. I have yet to find anything comparably close to Forscan for the GM market.
If you find something let me know but I looked back when I got our Yukon and came up with nothing close in comparison.

Jay2504 · 07-18-2018, 08:03 PM

I wish there was one. Thanks for answering. Jay

VN Warrior1966 · 07-19-2018, 10:22 AM

I had an interesting discussion with the service manager at my Ford dealership regarding this issue. I told him about this forum's discussion on this issue and he acted like it was totally the fault of the TT manufacturer. I reminded him that this is 2018 and virtually ALL of the truck & automobile manufactures are aware that LEDs draw less current than the older bulbs and surely would have made allowances in their computer software to detect the lower current thereby NOT flashing a warning to the driver that the "Trailer is Disconnected" when it clearly is not! I also told him about the software mentioned previously called Forscan and he said he'd never heard of it! So, my question now is where can one find this software? Is it something that a mechanic not working for Ford might possess? Because if that's the case, I'll just have to call around. But, I'm interested in any further suggestions. Many thanks to all that have contributed toward the solution of my dilemma!

dbledan · 07-19-2018, 10:41 AM

Quote:

Originally Posted by VN Warrior1966

I had an interesting discussion with the service manager at my Ford dealership regarding this issue. I told him about this forum's discussion on this issue and he acted like it was totally the fault of the TT manufacturer. I reminded him that this is 2018 and virtually ALL of the truck & automobile manufactures are aware that LEDs draw less current than the older bulbs and surely would have made allowances in their computer software to detect the lower current thereby NOT flashing a warning to the driver that the "Trailer is Disconnected" when it clearly is not! I also told him about the software mentioned previously called Forscan and he said he'd never heard of it! So, my question now is where can one find this software? Is it something that a mechanic not working for Ford might possess? Because if that's the case, I'll just have to call around. But, I'm interested in any further suggestions. Many thanks to all that have contributed toward the solution of my dilemma!

Full tutorial here
https://www.f150forum.com/f118/forsc...-truck-348987/

Best thing I ever did was get the odbII adaptor for this and change settings.

Larry-NC · 07-19-2018, 11:28 AM

Quote:

Originally Posted by VN Warrior1966

I had an interesting discussion with the service manager at my Ford dealership regarding this issue. I told him about this forum's discussion on this issue and he acted like it was totally the fault of the TT manufacturer. I reminded him that this is 2018 and virtually ALL of the truck & automobile manufactures are aware that LEDs draw less current than the older bulbs and surely would have made allowances in their computer software to detect the lower current thereby NOT flashing a warning to the driver that the "Trailer is Disconnected" when it clearly is not! I also told him about the software mentioned previously called Forscan and he said he'd never heard of it! So, my question now is where can one find this software? Is it something that a mechanic not working for Ford might possess? Because if that's the case, I'll just have to call around. But, I'm interested in any further suggestions. Many thanks to all that have contributed toward the solution of my dilemma!

Did you try Google? Here's the first hit.

Larry

VN Warrior1966 · 07-23-2018, 10:05 AM

Quote:

Originally Posted by dbledan

Full tutorial here
https://www.f150forum.com/f118/forsc...-truck-348987/

Best thing I ever did was get the odbII adaptor for this and change settings.

Where can I get this "odbII adaptor? Hate to admit this, but I'm totally clueless on this thing. Thanks!

dbledan · 07-27-2018, 01:13 AM

Quote:

Originally Posted by VN Warrior1966

Where can I get this "odbII adaptor? Hate to admit this, but I'm totally clueless on this thing. Thanks!

Follow the google doc link as it walks you through everything step by step. Item 3 under what you need is the link for the BT ODBII adaptor.

It walks you through everything you need to do.

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