2007 Escalade to 2007 Tahoe Taillight Conversion
Disclaimer: There is absolutely no guarantee of operation here or liability by the author or the forum as a result of anyone using this information. If you undertake this modification you do so at your own risk and may void your warranty if you damage your vehicle. *Note: this mod was just completed, so I would not consider it extensively tested. Likewise, I cannot attest to the longevity of the parts involved.
Parts required:
Qty (1) 15890422 2007 Escalade Taillight (US version) – includes the Escalade harness
Qty (1) 15890423 2007 Escalade Taillight (US version) – includes the Escalade harness
Qty (2) 5 to 4 trailer harness converter (Hopkins # 48845 or equivalent with internal blocking diodes )
Qty (4) 50W power resistors (Superbright LED’s #RL-650 or equivalent)[/ol]
Optional Parts:
Qty (2) 15803480 2007 Tahoe taillight harness (if you don’t want to cut up your originals)
Qty (1) 15262791 2007 Escalade driver side quarter panel upper appliqué
Qty (1) 15262792 2007 Escalade passenger side quarter panel upper appliqué[/ol]
Links for parts:
http://www.gmpartsdirect.com/results.cfm
http://www.superbrightleds.com/cgi-bin/store/commerce.cgi?product=CAR&keywords=&cart_id =2293254.7251&next=50
http://www.amazon.com/Hopkins-48845-Converter-Wirein-Wireout/dp/B0002RNSPK[/ol]
Theory of operation:
The 2007 Cadillac Escalade taillights use LED technology (for stop/turn/park – incandescent for reverse) vs. the 2007 Tahoe which uses incandescent dual filament bulbs. LED’s are low current devices whereas incandescent bulbs require more power. The vehicle circuitry in the Tahoe is designed to expect the load of two 27 watt incandescent bulbs for stop and turn circuits.
The Escalade taillights combine stop and turn into a single circuit, whereas the Tahoe has a separate circuit for stop and turn. Therefore, a circuit must be created to accommodate this requirement in order to use the Escalade lights in a Tahoe chassis.
The easiest way to do this is to use a simple trailer harness converter that is designed to adapt import vehicles with separate amber turn signals to a trailer that has a common light for stop and turn functions. Most of these converters contain blocking diodes (keeps current from separate turn and stop circuits from feeding back into each other). The Escalade taillight can be considered the “trailer” light for purposes of completing this modification.
The other requirement will be to simulate the electrical load of the incandescent bulbs. We will use power resistors to accomplish this function. The resistors should be at least 50 watt units that are suitable for mounting under the vehicle chassis. These units will dissipate power, so they can get as hot as a light bulb. Best to look for some that have an external heat sink as with the units pictured. If you don’t use the resistors, not much will work besides the park & reverse lights.
Installation instructions:
1. Obtain required parts
2. Wire the Escalade harness per the schematic
3. Install the converted taillights
4. Test & verify all functions (hazards, stop, turn, park, reverse)
Notes:
The Escalade lights have a different profile (angular) than the Tahoe (round). Therefore you might want to install the Escalade applique’ as well (some people call these vent caps) These come in black plastic so you’ll have to paint them to match your Tahoe
Because of the way the converter operates, you may notice that when you have your turn signal and stop lights on at the same time, the turn signals in the side view mirror and taillight alternate. The reason for this is that when the converter is passing through the +12v for the solid on stop signal, when it detects a +12v on the turn signal wire what it does is turns off the stop pass through for the duration of the turn signal. This enables the combined light to flash instead of being on steady because without the converter the stop would override the turn and the light would remain on.
Depending on your wiring/soldering skills, this is a 3-4 hour project (without applique’ change)
I recommend that you “mock up” your connections first (twist wires and wrap with electrical tape) then plug into the vehicle chassis harness from under the vehicle with the Escalade taillights laying on the ground (actually standing on end, upside down). You can do this without dismounting your stock Tahoe taillights and will enable you to test/troubleshoot while still being able to fall back to stock easily until you get the wiring correct.[/ol]GM makes a Euro version of the Escalade Taillight that would eliminate the need for the converter. You would still need load resistors, but you might want to research using the Euro versions instead of integrating the US versions into a Tahoe. I do not have part numbers for these or instructions on where to obtain them.
