Thunderbird, Cougar, and Supercoupe Information

Saturday, January 21, 2006

LED Tail Lights Background & Troubleshooting Information

The tail lights of a Thunderbird have always been among the cars most remarkable characteristics. The Jet turbine look of the original, the full width lights in '66, the futuristic aero lights of the late 1980's, and the eye catching LED tail lights of the Superbirds.

Background on the Thunderbird LED tail lights

Tail lights on '92 through '97 Thunderbirds are unique from other years. Light Emitting Diode circuits designed by Hewlett Packard are responsible for their mesmerizing glow. They are energy efficient, maintenance free, and last as long as 100,000 hours. This was one of the first automotive applications for the LED technology which will soon become status quo.

Repairing dim or burned out tail lights

Each tail lamp contains a circuit board which holds 20 LEDs. These are grouped as 4 individual circuits, 5 LEDs per circuit. Each circuit contains resistors to regulate current.

Over time, moisture can enter worn housings. Circuit boards corrode and resistors fail. When this happens, one or more groups of LEDs go out, leaving a characteristic pattern of dark spots visible throughout the tail light.

A simple solution to this problem is to replace the entire LED strip. Tail lamp housings are cut open, the bad LED strip is removed, and a working one is inserted in its place. Instructions for this can be found at the TCCOA. Sources for LED strips include the SCCOA classifieds, TCCOA classifieds, and ocassionaly eBay.

In the event that replacement LED strips are unavailable it is possible to repair a bad strip. This is a more complex solution and will require some electrical knowledge. The basic process involves diagnosing failed components, finding appropriate replacement parts, and installing them. Relevant technical information can be found on discussion groups at Google, and electrical hobby sites.

The original LED strips created by Hewlett Packard are becoming scarce, and discussions are in progress to replace them. In the future, aftermarket alternatives may be created using parts from various sources.

Replacing the Entire Tail Light

Sometimes replacing the entire tail light assembly is the best option. Doing so eliminates the need to cut housings open, search for hard to find parts, and perform tedious repair work. The only drawback is expense. New lamps cost considerably more than repairing a broken unit, especially if buying more than one.

Currently, new tail lights from Ford are about $100.00 depending upon location. New units can also be found at some online vendors such as Rockauto or Fivestarford. Purchasing tail lights used can help offset cost. These can be found on eBay, TCCOA classifieds, SCCOA classifieds, and similar sources.


Anonymous Anonymous said...

I may be able to fix the LED reflector panels on those Ford Thunderbirds from 1992-1997. But what is the Voltage and current rating on those LED's. The resistors are 33Ohms (orange, orange, black, gold) on each of those 4 circuits of 5 LED's.

The Light Emitting Diodes (LED's) are squared and have three prongs. 2 prongs that make the cathode and a center prong that makes the anode. I cannot find those Diodes anywhere.

March 22, 2009 12:25 PM  
Anonymous PIC said...

I posted a solution to fix a broken taillight here. The red LEDs usually have a 1.6 V voltage drop, which totals to 8.0 V. Assuming a battery voltage of 13.8 V, the resistor needs to drop 5.8 V, so the current would be I=V/R=5.8/33=18mA.

April 14, 2009 6:15 AM  
Blogger Hertzrider said...

Vishay makes a similar led except it has four solder legs so you need to snip one and bend the third one to fit. Part #TLWR7900 and is available from Mouser Electronics and maybe DigiKey.
The light wavelength is 624 for the correct shade of red.

May 25, 2009 11:22 AM  

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