Dim Brake Lights

[Deano]

I have Sylvania Zevo (?) 1157 LED brake lights. They have always been kinda dim, but I didn't realize how dim until we almost got rear ended while slowing down to pull into our driveway. The front turn signals are plenty bright, so I don't think it's a voltage problem. I had the same trouble when I still had my '79 back many, many years ago.

Anyone have any upgrades that might help me?

 

[AMC Diplomat]

I had a lot of problems with poor grounds in the sockets and poor grounds at the factory splices in the harness. I ended up getting a junkyard taillight harness out of a really mint K car that was in a head on collision, splicing in the license plate light and the end connector, and now I have bright working taillights. I'm not running LEDs though. But the intermittent ground problems were a nightmare on the wiring that was in there

 

[Camtron]

I have Sylvania Zevo (?) 1157 LED brake lights. They have always been kinda dim, but I didn't realize how dim until we almost got rear ended while slowing down to pull into our driveway. The front turn signals are plenty bright, so I don't think it's a voltage problem. I had the same trouble when I still had my '79 back many, many years ago.

Anyone have any upgrades that might help me?

Sequential LED brake light/turn signals. I have a kit I’ve been meaning to install for a couple years, just haven’t gotten to it.
I have however also had the dim brake lights in the past. It was a bad spade terminal connection on one of the lights that was causing the weak signal to all of them. Cut it off, stripped wire, crimped on a new terminal and stuck it back on the light. Was nice and tight compared to the old one and the lights were then, bright.
I’d unscrew that little carpet cover in the trunk for the taillights and check the wiring behind it going to each light.

 

[Deano]

I checked the grounds and they seemed to be okay. I used my multimeter from each socket ground terminal to the ground for the trunk light and they were solid connections. Of course that probably doesn't mean anything. Design flaw?

 

[LSM360]

I checked the grounds and they seemed to be okay. I used my multimeter from each socket ground terminal to the ground for the trunk light and they were solid connections. Of course that probably doesn't mean anything. Design flaw?

You said you have LED ones and still dim? I'd be thinking maybe you got some dim LED's and need stronger ones if they are still dim and everything else checks out. I have an LED dome light and it's dimmer than the stock incandescent. I've never had dim brake lights, just the problem of only one or two working when lights are on. That is usually resolved with cleaning or replacing sockets.

 

[Deano]

The Zevos don't have the LEDs on the very end. They are on the sides, relying on the reflectors to supply the illumination.

The metal on the end is a heat sink.

 

[AMC Diplomat]

Design flaw?

The K car sockets look like the same Mopar design as the M body sockets, but the plastic looked a 100 times better on the K car. I don't know if Chrysler was using crappy plastics on the AMC assembled cars, but the K car harness looked damn near new and came out of an 84, and the original harness in my 87 looked ancient. The sockets would test fine with a probe, but not with a bulb in place. It was absolutely maddening.

New, aftermarket, mopar style sockets are like $13-14 apiece at NAPA. The K car harness, with the bulbs, a sealed beam headlight, and a glove box latch were like $12 including tax.

Turn the lights on, pull a socket out of the housing, and see if you can ground it with a scrap piece of wire from the metal on the bulb cap to a bolt back there. If it gets brighter, it's a ground problem.

 

[Mikes5thAve]

Condition comes down to the car. The only ones I've has that didn't look good gad leaky tail lights or the trunk was always damp.
They are very finicky with the sockets and bulbs being clean and yeah ground issues.
Did you try normal bulbs or different led's?

 

[Deano]

Turn the lights on, pull a socket out of the housing, and see if you can ground it with a scrap piece of wire from the metal on the bulb cap to a bolt back there. If it gets brighter, it's a ground problem.

I did exactly that on all six sockets. No change.
What I meant by "design flaw" is just the angle, positioning, and the shape of the taillight housings, not necessarily the wiring. When the sun is anywhere behind the car, it seems like it's shining directly into the housing, eliminating the effectiveness of the lighting.

Condition comes down to the car. The only ones I've has that didn't look good gad leaky tail lights or the trunk was always damp.
They are very finicky with the sockets and bulbs being clean and yeah ground issues.
Did you try normal bulbs or different led's?

The housings, terminals, sockets and wiring to and from are all in very good condition. I tried different LED and incandescent bulbs with no difference.

Thinking about these;

1157 LED Bulb - Dual Function 27 SMD LED Tower - 2 Pack

LED replacement bulbs can fit vehicle tail lights, brake lights, reverse lights, turn signals or side marker lights. This 1157 dual-contact, dual-function bulb emits a 360° viewing angle for better, allover light emission with reduced hot spots. The bulb features a tower-style design with a...

www.superbrightleds.com

 

[FredMcJoe]

The Zevos don't have the LEDs on the very end. They are on the sides, relying on the reflectors to supply the illumination.

I bet that's the trouble, since the LED has a narrow angle of the spread of light whereas an incandescent is 360' lighting... try one with LEDs all the way around and then a couple of LED sections on the end of each bulb. Isn't there a new style called "bright LED" too?

 

[Ash_Whole]

put in a proper 1157 and see. LED bulbs are mostly junk