So i put some LED tail lights into my 85. Now when i step on the break pedal the "stop lamp" light comes on. Does anyone know why this happens? All the lights work.

 

the Dash light is set to a resister draw i think.

Ok you hit the break the power goes from dash to light and the light sucks up a certian amount of voltage when the light goes out the closed loop is broken and the dash unit knows that this means its out.

LED doesnt draw much so my guess is that the draw isnt enough for the dash unit to realize its ok.
I installed the same thing but i noticed the LED wasnt bright enough in the red lens.

but its just a guess.

 

the LED lights don't have the resistance like the incandescent bulb does so the system thinks the bulb is out. search to find threads that tell about how to fix this problem. i think u have to add a resister to the system somewhere.

 

was i right? i think so.
Michael is on to something, if you put the right resistor tight in the line befor the bulb it should not trip the light, but you will not know if its really out.
check the FSM to see what the resistance is and also try a search on if the stock bulb type has a built in resistor?

 

Mine always came on when I hit the brakes and all the bulbs were new. I thought it was supposed to do that. lol. I guess I need to check some more wiring.

 

mines always done it when all bulbs are bright and new.... i just learned to forget about it

 

Find the required resistor and wire it into the circuit, the system is looking for the proper resistance in the circuit assuming it has regular filament bulbs.

 

lol mine just comes on every now and then

 

The reason your brake lamp indicator is illuminated is because the car thinks the bulb is burnt out. LEDs consume less power, through a lower current. In the event of a burnt out bulb, the car sees the branch as an open circuit, illuminating the indicator. Open circuits have zero current flow. An LED lamp will draw such little current, the car assumes the bulb has burnt out.

If you add a power resistor to the circuit, you can trick the car. A resistor in parallel will draw current, in much the same way a light bulb would. You will need a high power resistor, one rated at least 30-50 watts.

Typically a 6 Ohm 50W resistor for each bulb replaced is needed. Remember these resistors are dissipating power, which means they are generating heat. The higher the power rating, the cooler they will be. The 50W rating also assumes you are mounting them to a heat sink, so in open air their power rating will drop.

Points to remember!

• Use a suitable high power resistor.
• Wire them in parallel, NOT series.
• Use one resistor per bulb.

These resistors can be purchased from electronics supply stores, eBay or online retailers such as: RL-650 Tail Light Load Resistor kit

Also, I think you will find the LED replacements are not as effective. Most do not toss light onto the reflector as the incandescent bulbs did.

 

The indication system is looking for a current draw. Otherwise the brake light warning checker operates that exact way

Resistors have to be in parallel, not series. If they are in series they will drop the voltage to the lamp, making it dull. Stock bulb kind of had resistance built in as the coil in the incandescent bulb is a resistor. It just makes light as well

Check your brake fluid level sender. The brake indicator is tied to the bulbs, fluid level and parking brake.

 

I'd like to know where you got your tailights. Unless you made them, i'm really interested in some aftermarket tailights.

 

I bought and installed a complete set 2 yrs ago for some $75 and they were hopelessly dim in sunlight. I actually had people at stop lights tell me my brake lights were broken. Maybe aftermarket tech has improved since then - it will eventually - but be warned you could be in a world of hurt if these under-perform in an emergency.

New OEM LEDs are a completely diff kettle of fish - far more sophisticated (they use a complete, specialized housing/power supply, etc) and likely eye-wateringly expensive. This too will change. meanwhile I think Thomas Edison is still your best friend...

Stu Aull
80GS
Alaska

 

Most good aftermarket LED manufacturers that make bulbs to replace the common 2057 and 1157 etc bulbs have resistors built into the bulb themselves that alleviates this problem.

Statements above are correct for why the STOP LAMP light is on.

 

85 GSL FB NA, totally stock.

Sorry to resurrect this thread, as I know the topic already has been covered in detail here and elsewhere; but I'm hoping to get some advice on why my load resistor installation does not work... :-(

About a year ago I installed LEDs in my taillights for all bulbs other than turn signals. These are bright and awesome--but of course give me the STOP LAMP warning light whenever I apply the brake. Ignoring it has gotten old, so a couple weeks ago I elected to go the load resistor route, with this kit: 6 ohms, 50 Watts

The instructions are pretty straightforward (see attached).

So based on these instructions, and the wiring diagram for the taillights (attached, from FSM, Wiring Diagram, p. 50:24), I connected the load resistors (one for each taillight assembly) *in parallel, between the GREEN wire on the harness connector and the BLACK (ground).*

And yes, it was the solid GREEN wire that I used. No stripes.

Unfortunately, I still get the STOP LAMP warning light in the gauge cluster...

Can anyone point out where I may have gone wrong? I figured this was such a simple fix, and the Stop Light circuit was so clearly labeled in the wiring diagram that it should be quick and easy...

 

take the guage panel off and remove the light bulb from the stop light indicator

 

The reason the warning is still on because it doesn't see enough load, even with the 6 ohms. Do you have a load resister attached to each LED light? Looks like there are two per side.