Adding additional bed lighting to existing bed lights - issue

[c-ne-elk]

With my Diamondback bed cover on my truck the bed is super dark at night. So a couple of us have had the idea to put some LED strip lights in the bed and to just tie them into the back of the existing bed lights so you could operate them from the bed switch or the cab switch for the bed lights.

We are having an issue with these additional lights tripping the BC Module if your headlights are on and your door is open. They come on for about a second and then they trip the BCM. They work fine if you just have the bed lights on. We are doing this on two identical trucks and having the same issue with both trucks.

We have two 60" strips connected to the lights, one on each side. I disconnected one strip (the drivers side) to where just one is connected (the passenger side) and that seems to be working just fine even with all the other lights on. It is no longer tripping the BCM.

The strip lights do not have a relay on them.

Any clue as to what is causing this and how it might be remedied?

AND as an FYI, to reset the BCM, you don't have to disconnect your batteries for 10 minutes as some have said (but this does work). If you double click your remote to lock the truck which puts the computer in sleep mode for 10 minutes and restart your truck it will reset the BCM.

Thanks in advance for any help!

 

[MiTremor906]

I thought someone on here said they disconnected one of the factory lights to make it work but can't remember for sure. I'm interested in this though as just the other day I was thinking it needed more light.

 

[c-ne-elk]

I tried that.

When I had them both connected it would blow the BCM even with the headlights off and doors closed.

When I disconnected one of the original bed lights it worked fine until I turned the bed lights on with the headlights on and the door open. It would then blow the BCM.

Not sure if the door open or headlights on separately as I never tried it with just the door open or just the headlights on.

 

[Daimyo68]

Did you try pulling the code from the BCM?

The BCM is most likely seeing an Over Current issue (increase in amperage draw even though it is very small) with the added led strips.

I've seen people add relays to their lighting to avoid this issue, but never personally done it myself.

You could also shorten each strip by half. Being that 1 full 60" strip does not trigger the BCM, it would make sense that 2, 30" strips should be fine

 

[c-ne-elk]

One strip is very bright and no matter which lights I turn on in the truck, it does not trip the BCM. But you know how it is with lights....

 

[c-ne-elk]

Did you try pulling the code from the BCM?

The BCM is most likely seeing an Over Current issue (increase in amperage draw even though it is very small) with the added led strips.

I've seen people add relays to their lighting to avoid this issue, but never personally done it myself.

You could also shorten each strip by half. Being that 1 full 60" strip does not trigger the BCM, it would make sense that 2, 30" strips should be fine

Ahhh... good idea! Will check the BCM code tomorrow, getting too late for us old guys tonight!

 

[NL-Tremor]

It sounds to me like the extra load of the lights is simply overloading the circuit - when BCM is at peak load (i.e. head lights and interior lights) it seems like it's simply overloaded and "trips" to protect itself - that's my guess anyway.

The best way to solve this is likely to have your additional lights run off a relay with it's own power source and have the OEM bed lights only send signal power to the relay to prevent overloading the circuit.

 

[Canyon Trekker]

Once again, these posts are valuable information. I too am going to install lights under the D-back cover and will now avoid this fault. I'm going to run a relay tied into the bed light circuit and power the lights from the upfitter switch number 6, which I ran to power my camper/bed power, that I use for accessories and external lighting. I have the upfitter switch in the constant on position with ignition off. In this scenario, I also have the option of turning the extra bed lights off by turning the upfitter #6 switch off if not needed.

 

[c-ne-elk]

Here is what we have figured out:

6 amps of additional lights will cause the BCM to shut down the bed lights due to detecting an over current if you turn the bed lights and head lights on at the same time with the engine running. If the engine is off, it will work fine. Not sure what the extra draw is when the engine is on.

If you disconnect the 2 factory bed lights, 6 amps of additinal lights are still too much if you turn everything on. They will work fine until you turn everything on.

Adding 3 amps of lights will not cause a BCM shut down due to overcurrent with everything on. We have not tried 4 or 5 amps but I am pretty certain the factory bed lights are at least 1 amp so I do not see 5 amps as working.

Just as an FYI, the LED Strip lights that I have been looking at are 0.3 A for a 12" strip or 0.6 A for a 24" strip. In theory, I should be able to run 5 ea 24" strips but will probably run 4 ea, 2 on each side.

 

[MiTremor906]

Here is what we have figured out:

6 amps of additional lights will cause the BCM to shut down the bed lights due to detecting an over current if you turn the bed lights and head lights on at the same time with the engine running. If the engine is off, it will work fine. Not sure what the extra draw is when the engine is on.

If you disconnect the 2 factory bed lights, 6 amps of additinal lights are still too much if you turn everything on. They will work fine until you turn everything on.

Adding 3 amps of lights will not cause a BCM shut down due to overcurrent with everything on. We have not tried 4 or 5 amps but I am pretty certain the factory bed lights are at least 1 amp so I do not see 5 amps as working.

Just as an FYI, the LED Strip lights that I have been looking at are 0.3 A for a 12" strip or 0.6 A for a 24" strip. In theory, I should be able to run 5 ea 24" strips but will probably run 4 ea, 2 on each side.

Do you have a link for the lights you are using?

 

[c-ne-elk]

These are the 60" ones we used. Got them off Amazon. Not sure which 24" I am going to go to. Still just running one of these strips, it is crazy bright by itself!

 

[Mike Alcocer]

How do you have it wired? I have been meaning to look up the wiring for this system but have other projects ahead of this.

Ideally I would take all of the stock lights off their current circuit. Have the factory wiring power the coil side of a relay and an independent power source run to the switch side of the relay to power the factory lights and the new LEDs.

 

[Rock Taxi]

I wired mine to the running board lights plug, the gray plug on the outside of the frame under the rear doors. Activates with the bed light switch in the bad and handles the amperage just fine.

Ed

 

[c-ne-elk]

How do you have it wired? I have been meaning to look up the wiring for this system but have other projects ahead of this.

Ideally I would take all of the stock lights off their current circuit. Have the factory wiring power the coil side of a relay and an independent power source run to the switch side of the relay to power the factory lights and the new LEDs.

I just spliced into the existing left & right bed lights wires right before it goes into the lights.