300 td tail bulbs - different brightness?

[pkmorgan17]

My 82 300 TD tail lights glow at different intensities. The brake lights come on with equal brightness but when the car is just driving at night the two tail bulbs are not equal in intensity. What numerical bulbs should be in there?

Hail the forum!

[MarkM]

Brake light bulbs are the larger single filament 21 watt bulbs. If you happen to have the correct bulbs in there, replace with new ones to see if that fixes the problem. Also, clean contacts to ensure good electrical contact, and check plugs, etc. If problem persists, check the reflective surface inside the housing to see if corroded on one side. If so, you may need a new housing.

[Ken300D]

I had the same thing on my '82 300D when I first got it. I think if you check the bulbs they will probably not be the same. They are supposed to have a 10-watt German-made bulb. Available here at FastLane and at Performance Products for 84 cents each. I bought a handful to keep as spares and to replace the "close but not quite" American bulbs someone had put in the car.

Typically the American bulbs will have a brass colored base and the German bulbs are silver/chrome/aluminum colored.

Ken300D

[240 Ed]

Mark M

he was asking about tail light bulbs and I think 10w is correct.

I don't see anything wrong with getting a 1056 american bulb, get two for a matched set.

All this talk about german bulbs vs. american bulbs, is sheer nonsense anyway.

[be459]

If you do not use the OEM bulbs, the Cruise control may not work.

David

[MikeTangas]

Take a read at this link:

Brighter Brake Lights? 190SL

Then take a look at your reflectors inside the tail lights. Might be part of the problem.

[240 Ed]

This is complete nonsense.

I don't know where this myth started, but it doesn't have any logic to it. IMO

[be459]

Terminal #8 of the Cruise Control Amplifier has a wire going to the brake switch where the brake light assemblies are attached. The Service Manual stated "FOR CRUISE CONTROL TO BE ENGAGED, TERMINAL 8 MUST SENSE GROUND THROUGH STOP LIGHTS. WHEN BRAKE SWITCH IS CLOSED, GROUND IS ELECTRICALLY REMOVED."

Studying the diagram more, you will find that a green wire from the Cruise Control Actuator connects to the same terminal of the brake switch stated above. It looks to me that a so-called "clutch solenoid" in the Cruise COntrol Actuator unit is energized by running electricity thru the green wire to the filaments of the brake lights, then to the ground.

If the resistance of the filaments is too high, I am very sure the Cruise Control Actuator will not work because there is not enough current to energize the solenoid or it may not work properly. If the resistance is too low, can that damage the amplifier? I have no answer but I have learned from this forum that a high current flow thru the coolent pump may damage the A/C control unit.

On the safe side, I just use OE bulbs, at least for the brake lights. The price is not that must different from other brands.

David

[mikemover]

The one on the driver's side is probably very dirty, especially on a diesel, because when you're sitting still, all of that diesel smoke is floating right up into your taillight on that side. Take it apart and you will probably be amazed at how dirty it is. I did it on my car and it made a noticeable difference. I should have done the "chrome paint" thing while I was at it...wish I had thought of it. I'll probably take both apart soon and paint them.

Mike