I bought a Spyder headlight kit to install in my 2012 GMC Sierra 2500HD. As part of the installation, I needed to splice into the parking/turn signal lights. I cut the wires to the one of the bulb to determine which wires controlled the signal and which controlled the parking lights. After trying to install it, there was a problem with the headlights and I had to remove the new ones and reinstall my old ones. So I used a buttsplice to reconnect the wires again, back to the bulbs. After doing so, neither the parking lights nor the signal worked. I checked and there was a fuse blown on the parking lights so I replaced that. The parking lights work but the signal does not. It just flashes fast, but the lights do not flash. I checked the fuse for the signal and it was NOT blown. So this is where I stand:

*Parking lights work just fine. Bulbs illuminate as normal
*When I turn the signal on, it immediately flashes fast on my dashboard, the front signal light do not work (nor does the mirror signal) but the back signal light work...just flashing fast.
*When I turn on the hazards, it flashes normally on my dashboard, the other front signal flashes normal and fine as well as the 2 back signal lights. The front one in question does not signal at all.

This cannot be a wiring issue as I labeled all the wires are reconnected them the same way they were originally connected. Is there another fuse or something else that could be causing this? Would replacing the bulbs help (although they illuminate just fine during the parking light mode)?

 

I would go back to the butt splice and redo it. Sounds like a poor contact in the splice. Usually the signal light flashes fast when a bulb is burned out or in your case probably open (no connection) to the bulb.

 

Thanks TMW.

It was actually another fuse. A fuse that controlled the dome and the driver turn signal, even though this was the passenger signal. Regardless, it is fixed.

Thanks again for the reply!