Ahsai

I see now. You can try this: just wire one 6 ohm 50w resistor in parallel in one of your DEPO lights, inside the DEPO light cavity. That should solve your problem.

injurylawyer

Each of the Depo tail lights already have a 50amp 6 ohm installed.

Not sure of what you are saying...should I add another?

The cruise control issue became apparent with the 3rd brake lights and the one in the recess behind the rear wind screen is easy since the recess is metal and I can use 3M double sided tape.

The issue I am having is once I connect the resistor to the 3rd brake light in the spoiler, where do I 'fix/secure' it...on the inside plastic cavity of the spoiler, behind the LED housing, etc.

Thanks for your continued help.

Ahsai

Yes, I got the all of the above. Since each 3rd brake light (one on the spoiler and one below the rear window) consists of seven 3W bulbs so each has 21W of load, identical to your regular brake light bulb. Therefore, the DME expects to see a total load of 21W x 3 (or 63W) when you press the brake. It doesn't care and can't tell where the 63W comes from since all the bulbs/resistors are wired on the same circuit. With only the DEPO built-in resistors, the load is closer to 42W therefore you need to add ONE 6 ohm resistor to load the circuit to make the total load closer to 63W.

Try that first. It won't damage anything (as long as you wire it correctly) even if it doesn't work so no worries there.

krafty

I do not remember a resistor being mounted on the 3rd brake light bar. I believe the resistors in the tail lights were enough to warrant not requiring one for the 3rd light. I'm not 100% sure though.

alpine003

This is normally the case in most situations, however some lights (Spyder branded ones in particular) had some reverse polarity issues before IIRC. I'm running LED tails without any issues and I don't have any resistors in the LED 3rd brake light either.

injurylawyer

Thank you. Good idea. You are wealth of knowledge...and with that being said...

Would you happen to know which (color) wire is the positive/hot brake wire and which is the ground that I would tap into to run the resistor parallel?

My car is a '99 996 C2.

Ahsai

It's easy when you have the wiring diagram

There should be 3 wires connected to the stop light socket. The black wire is the positive for the stop light and the brown wire is the ground. The red wire is the positive for the rear side marker (which you should ignore). So you can just wire the resistor on the black and brown wires to test it.

alpine003

Did you make sure you didn't blow any fuses and the small connector is connected with the right polarity?

Seems weird you would have this issue on a '99.

injurylawyer

I think you are thinking of the Spyder style tail lights which require you to use the factory harness. The DEPO lights are truly plug and play...it has the single 6 pin connector.

I checked the fuse which is a 15w located at B-7 which is labeled 'brake light/cruise control' and it is just fine...brake light works fine too.

I think the issue is the resistance...on the Spyder lights you are alluding to, you use the conventional incandescent brake lights from the original lights...the DEPO is 100% LED which make the resistance fall too low...

That is my take.

So, I just need to know, from the rear tail light harness six pin connector coming from the body of the car, which of those 2 I need to bridge with the resistor...it would need to be the power for the brake lights and the neutral.

injurylawyer

Ahsai

Thanks for your continued help.

I think the colors of the wires you identified are the colors from the tail light assembly harness....with the new lights, there is a built in harness. So I was thinking of running the parallel resistor across the ground and power for the brake lights somewhere between the body and the 6 pin connector.

With the diagram, would you know the color of the wires or pin locations of which of the 2 of the possible 6 pins I would need to bridge?

Thanks again...

Ahsai

On the 6 pin connector on the car side, the Black/Orange (pin 4) is the +12v for the brake light and the brown is the ground for the brake light (and for all the other lights too).

alpine003

Gotcha, I did my mods a few years ago when they didn't have this version yet. Gotta keep up with the times...

injurylawyer

'YOU DA MAN'



Got home and pulled the DEPO LED tail lights. Put the OEMs in and went for a test drive. Cruise was working again....so we know for sure it was the LED tail lights.

So, I had 50w 6ohm reistors on hand. I pulled the lights and as in videos posted by Delray Customs, rather than have it dangling or attached to the plastic housing, spliced the sleeve around the six wire harness to make a one inch gap about 4 inches from the grommet. Pulled the orange/black tail light positive and the brown ground that YOU pointed out to me and ran them parallel. I mounted them on the back of the cavity near the other factory resistor that came with the DEPOs (presumably the one for the blinkers to prevent hyper blinking)---Did same on both sides (x2).

Just came back and my cruise is working again!

Thanks for your insight.

Perhaps it is a '99 thing because the DME changed from '99 (first year of production in US although in Europe I understand that it was actually introduced in '98) to the later models. The cruise system is presumably different to later models in that my throttle is not electronic as they introduced on the Turbo and then later years (drive by wire vs. e-gas). Perhaps that system on my '99 is more sensitive to the resistance....

Reading some of your earlier posts, 50w on both sides may be 100w total which is more than the 63w needed to equal the three brake lights. Overkill?

Thanks again...saved me a trip to the shop...

Ahsai

When selecting the wattage of a resistor, the rule of thumb is select at least double the actual wattage consumed so you have >=100% safety margin.

Skits2112

Hi all, want to add to this older thread as I think my issue is related....namely, I've upgraded my factory tail lamps and both 3rd brake lamps to LEDs. Never had a problem with the LED tail lamps or the deck LED 3rd brake lamp but could not get the spoiler LED lamp to work. The original lamp does work well however. So, I added 2-50w resistors to the tail lamp wiring but the LED spoiler lamp still won't light.

Can anyone suggest why?