Automotive Cornering light applications for 2015 Chevy Tahoe LS


Newly Enlightened
Oct 27, 2014
90 degree (especially left) turns at poorly illuminated intersections are made extremely difficult by the poor lateral dispersion from low beams and by the significant blind spots created by side mirror and windshield pillar. Is there any experience out there with 'cornering light' applications for Chevy Tahoe or similar vehicles with same problem?


Mar 26, 2004
Welcome to the board!

It is fairly easy to create a good, effective cornering beam setup that works like factory-installed lamps (comes on with the turn signal, produces a safe and effective cornering beam, remains lit for a couple of seconds after the turn signal cancels after a turn). The way to do it is with a pair of carefully-chosen fog lamps controlled by a special lag-release relay (something like this). It's been awhile since I put one of these setups together, so I'd have to sit down and do some circuit plots to figure out if you can get away with one timer relay or if you need two (one per lamp). You would need some regular relays, too. The lamps (I usually use an H3 fog lamp such as a Bosch Compact 100 equipped with a 35-watt H3 bulb -- 55w is too much) get mounted at the outboard extremities of the front bumper, pointed sideways and aimed conservatively downward to avoid the danger of glare to other drivers. The "secret" to how this works is that the lag-release relay's control terminals get tapped into the vehicle's turn signal which has a flash rate of 1 flash per second, plus/minus 50%. So as long as the turn signal is active, the relay never releases because its lag is 2 seconds. The cornering light therefore stays lit. Then the turn signal cancels out after the turn, the 2-second delay times out, and then the cornering light turns off.