Installing a Third Brake Light/Cargo Lamp Combo

[LakeOzarkMJ]

Longtime lurker, first time poster.

 

I've seen a few posts on installing a third brake light and separate ones on a cargo lamp, but I hadn't really seen one on doing a combination that answered my questions. I saw one that was for a topper, but not the cargo lamp area.

 

Ultimately, I want the cargo lamp to hook up to a (to be installed) OEM cargo lamp switch in the dash, but then use an aftermarket third brake light/cargo lamp combo over the bed. I've seen a few OEM ones from an old Ford Ranger, but I think I'll stick with something newer for simplicity's sake.

 

A couple open ended concerns and various questions: 

 

I've seen it mentioned I may need a third brake light logic module. Is this just if I'm tapping into the taillights? I'm not sure what's going to be more difficult: tapping into the brake pedal switch or the tail lights. I imagine running something in the cabin would be easier than going all the way to the rear of the truck.

 

I saw there were issues with the third brake light flashing when you tap the brake. How do I make sure it's running whenever the lights are on? Should I use the module and tap into the brake pedal and the front headlights so it knows when to turn on? Then separately wire and ground the cargo lamp?

 

This truck has been a learning hobby and I'm very new, so feel free to correct me where I'm not making sense or even asking the wrong questions. I may just give up and do a factory cargo lamp only, but I think having some extra safety from rear ends in a non-airbag vehicle + cell phone distracted drivers may be helpful. I attached a couple photos of the parts I'm considering. 

 

TIA!

[Eagle_SX4]

This is what I did with mine.

 

For power I just tied in to the brake light switch on the pedal. I used the factory wiring for the cargo light. If your truck is 86-90 it should already have the wiring for the cargo lamp. If it is 91-92 it won't have the wiring unless the cargo light was actually installed.

[AZJeff]

My MJ has a third brake light/cargo light from late 1990’s Ford Ranger.  It works quite well.  The brake light is tapped into the circuit going back to the taillights through the floor of the cab.  
 

The cargo bed lights are tapped into the light switch connector.   All joints are soldered and sealed with heat shrink tubing.

 

be sure to use the appropriate gasket (rubber seal) between the lamp housing and the sheet metal of the body to prevent water intrusion.

[Eagle_SX4]

1 minute ago, AZJeff said:

The brake light is tapped into the circuit going back to the taillights through the floor of the cab.

Does that make the third brake light flash with the turn signals? I connected straight to the brake light switch so I would not have to deal with the turn signal switch.

[LakeOzarkMJ]

3 hours ago, Eagle_SX4 said:

This is what I did with mine.

 

For power I just tied in to the brake light switch on the pedal. I used the factory wiring for the cargo light. If your truck is 86-90 it should already have the wiring for the cargo lamp. If it is 91-92 it won't have the wiring unless the cargo light was actually installed.

This is great info. Mine is a 92 without the cargo light. So does the third light only activate when you depress the brake? As in it won't operate as a running light when you turn them on/increase in intensity when you depress the brake?

[Eagle_SX4]

8 minutes ago, LakeOzarkMJ said:

So does the third light only activate when you depress the brake?

Yes that is correct. It only lights up when you hit the brakes.

[Pete M]

I attached this one to the brake pedal and a custom switch on the dash.  works nice.  

 

 

[LakeOzarkMJ]

Thanks for the advice and inspiration everyone. I think I'm going to try one of the Dakota 3rd brake & cargo lights. Looks OEM. I'll see if I can splice the leads for the brake and the running light, then run the cargo lights to the dash switch. Wish me luck haha