I had to remove the headlight housings to troubleshoot and replace an aftermarket HID headlight ballast on my '07 Tahoe LTZ. Since I had so work so hard to get the housings out enough to get access to the back (problem #1), I decided to upgrade the other bulbs to LED and got the Sylvania lifetime warranty ones to match the incandescent ones. However, when I put the LEDs in, neither the driving, nor front turn signals work, and the tail turn signals flash really fast. Put the old bulbs back in and they all work normal. Any ideas since these LEDs are supposed to be plug and play? Just wasted about 4 hours trying to get this simple upgrade done.
So few LED bulbs are truly plug and play. The voltage is different for LED’s so the truck thinks there is a bulb out. The rear is hyper flashing which is by design so the user will ideally check for a burned out bulb on the side that’s affected. The fix is having to wire in resistors on all LED bulbs.
LEDs have a directional current requirement, meaning that they will only work when inserted into the bulb socket in the proper direction. Unlike incandescent bulbs, which can be inserted into the bulb socket in either direction and work, the LEDs will work in only one direction in the bulb socket. If you insert the LED into the bulb socket, and it does not light, remove the LED and rotate it 180 degrees and re-insert it into the bulb socket, and it will work. As stated by BG1988 and EX Euro Driver, hyper flash can only be eliminated by a reprogramming of the BCM, or by the installation of resistors in series with the wiring of the bulb socket. Reprogramming the BCM is not trivial or cheap, so you will need someone else to do it. The resistors can be purchased online, usually at the same site that you purchased the LEDs, or at some of the local auto parts stores. Personally, I kept the hyper flash, as I believe that it is more noticeable to other drivers on the road, when signaling my intent to make a turn. I understand that hyper flash is illegal in some states, so you may want to check out the regulations in your state.
You might wanna check your local auto parts store to see if they carry an Led electronic flasher that’s compatible with your vehicle . I know they make them for all 99-06 Tahoe’s and Escalades . It’s the flasher responsible for all of your signal lights . Not too certain on your specific year .