Accessing cargo bay wiring near saddle/top box

[grandoak]

After putting LED bulbs in for cargo bay lights, I find I need to add resistor. I believe one (1) will do as if I use incandescent in one side with LED in other, full light occurs.  However, access to bulb sockets is limited in the saddle, or top, box where socket is found and wiring almost immediately exits front of box, towards cab, where there seems to be large space between top box and cab, or front of cargo bay.

How do I can access to that unused space along side of cargo bay to add load resistor so it isn't at risk of being ripped out if inside the saddle/top box?

If another easier location exists, I would appreciate knowing that too.  I've thought about under dash near switch, but with remote start and all, that space is getting a bit cramped.

Thanks in advance for any helpful responses.

 

[MS03 2500]

You may want to try flipping the bulb that is dim.

 

[redheadedrod]

If you find you DO need access to the back of the bulb socket there are a couple ways to do it.

On the interior there is a plastic cover that is over the actual wall. You can remove the retainers and the 4 bolts on the strap hooks and it will pop right off giving access to the clear cover. The clear cover is only held in place by two screws. Doing this by memory and I say that because you might look at the clear plastic cover and see the 2 screws without removing the plastic cover over the wall.

The other method is just removing the 4 bolts on the hold down straps and open your saddle bag, you will see a small bolt holding the latch mechanism to the outside of the truck. Once removed the whole saddle bag assembly will come off. Be aware that the rubber the covers sit on is connected to the rubber around the back window so you will have to pull it off to remove the saddle bags. Do NOT rip this rubber as you then would have to replace the whole seal.

The wiring comes from the top of the cab under the third brake light so you COULD just do any modifications there.

HOWEVER, I believe you are confused. You should NOT need to put resistors on ANYTHING LED other than turn signals or brake lights. For the cargo lighting the truck does not have a "bulb out" indicator that I am aware of so putting a resistor on the line will do nothing for you except waste electricity, wear out the wiring from the extra load and maybe dim your light some.

 

[grandoak]

You may want to try flipping the bulb that is dim.

Both are dim if they are LED and flipping doesn't help.  It's a too low a draw problem, similar to hyper-flash in turn signals.  For those, I simply purchased a new flasher that works with standard and LED bulbs rather than adding resistors.  Granted twice the price, but cleaner solution.

-- GrandOak

 

[grandoak]

The wiring comes from the top of the cab under the third brake light so you COULD just do any modifications there.

HOWEVER, I believe you are confused. You should NOT need to put resistors on ANYTHING LED other than turn signals or brake lights. For the cargo lighting the truck does not have a "bulb out" indicator that I am aware of so putting a resistor on the line will do nothing for you except waste electricity, wear out the wiring from the extra load and maybe dim your light some.

Thanks, the third brake light on top access sounds like the cleaner and faster solution. 

Also, on my 03 Z71 1500 it appears there is a "bulb out" indicator because like I said, with both LEDs in, they are extremely dim, but if even one of them is standard incandescent then LED is at full 6000K lumens!  It also doesn't matter which side is LED vs Incandescent either.  I read somewhere that Sylvania LED was not supposed to have the "bulb out" problem, but that turned out to be false.

Another thing I noted is that vanity mirrors and cargo lights appear to be on same circuit as the "bulb out" effect is only at those two locations.

I did get a new flasher for hyper-flash on turn signals, and brakes seemed to be fine, unless they also are tied through the flasher unit.

--GrandOak

 

[redheadedrod]

Brake light issue is only if your cruise control doesn't work. If you lose cruise control when installing LED's in your tail lights then installing a resistor on the passenger side takes care of it. (I had this issue in my '03 )

I replaced my Cargo lights with LED strips and sometimes they are really bright and other times not. I figured either one of the connectors I did was not correct or the strips just suck since they were real cheap units.

Also your cargo lights have a plug behind the sail panels as well. The inside portion is REASONABLY easy to remove but requires removal of the third brake light. Without the third brake light the inside sail panels can be removed by undoing the four plastic "screws" on the end and then lifting the unit up. There is a plastic clip but if you rise the panel it will lift right off without breaking it. You will see a quick connect connector behind the panel. So either way.

 

[grandoak]

Sail panels are an even better solution cause they don't have to deal with double sided tape.

So you're saying each side runs up it's sail to top then junctions by 3rd brake before running into cab, and I assume through header panel of cab.  Guessing it must also then run down someplace to join harness under center console or up front directly into dashboard.

 

[redheadedrod]

The lighting for the third brake light and the cargo lights in my '03 come out at the top of the cab under the third brake light assembly. My truck has cargo lights on both sides. The cargo lighting runs behind the inside sail panel on each side and to the back side of the saddle bags. There is a quick connect connector to allow you to disconnect the cargo lighting from the main wire harness under the sail panel for that sides cargo lighting.

I can only vouch for my truck, other years COULD be different but this is how MY truck is.

 

[enoniam]

so putting a resistor on the line will do nothing for you except waste electricity, wear out the wiring from the extra load and maybe dim your light some.

I'm sorry, but this is so incorrect.  Even a roughly sized resistor isn't going to "wear out the wiring" and putting it in parallel with the LEDs (in order to increase the circuit's current draw) isn't going to dim the lights - he's doing it to increase the light.  As far as waste electricity, it isn't going to be consuming electricity unless the lights are on, which isn't usually that much at least in my case, and if sized appropriately only going to be approximating the "current" current draw through the incandescent bulbs.

That said I suspect dirty contacts on the switch / relay that is providing the current.  I don't think there is a relay in this circuit so that leaves the dash switch.  Can either see if you can replace this with a replacement switch or wire in another switch of your choosing and location.  I've had a switch near the tailgate in my truck for nearly 15 years now - it was one of the first mods I did to my truck.

One of the easiest things is what you were considering - installing a resistor.  Keep in mind Ohm's law when sizing (V = C * R) for resistance and power requirement (P = V * C).  (I've used C for current - often current is represented by I in these equations.)

Another easy thing to do is to leave one of the bulbs in the circuit and wire the LEDs in parallel to it.  Your own experimentation has shown that leaving one bulb in the circuit leads to good results.

 

[redheadedrod]

By wearing out the wire I am talking about if you use a load resistor that is going to pull 50 watts on a circuit that is setup for 15 watts your going to "wear out" the wiring by burning it up assuming the wiring is under sized for a 50 watt circuit plus whatever the LED's are pulling. (Anyone that has pulled apart a wire and seen it black would see what I am calling a "worn wire")

Assuming the lighting is powered by a relay, or on off switch, a resistor should do absolutely nothing other than dim the lighting and wasting power. If you are putting the resistor in parallel with the lighting as is the need for turn signals and brake lighting (for cruise control) your bypassing some of the amperage around the light and depending on the system can be causing the lights to be dimmer. But certainly using more power as it is released as heat from the resistor...

If put in series you limit the voltage to the lighting causing it to dim some.

So when I say "wear out the wire" I am talking about the changing(Burning off/Oxidizing)  of the copper in the wire because of the high temps from using under sized wiring. Not like wearing out a bearing or something mechanical.

 

[enoniam]

You are really missing his point...