The other day someone posted that the flashers in the Hummer were weak when a trailer was attached. I too experienced this problem and I just yesterday went to the auto parts store to get a replcement set. There are two round cans (mine were tin colored) on the black plug block above the fuses area. You get to them through the access hatch in the driver cab area. They pull straight out (wait till you get new ones before pulling).

As for what to get, there were three levels of units at the store I was shopping, regular, heavy duty, and extra heavy duty, as well as electronic and thermal, as well as a number of pin configurations. The Hummer uses a two terminal US standard unit. Regular is 2 lamps, heavy duty is 2-6 lamps and extra heavy duty is 2-12 lamps. I got the extra heavy duty (if able to handle more current, the contacts should last forever). As for electronic versus thermal, I got the electronic. I doubt there is any difference in performance, but the reason the stock units blink too fast is that they are thermal units and they heat up too quickly because of the extra lamp load, while the electronic unit seams to have a one-shot, so that the variation will be on voltage rather than current.

You will need two flasher units (turn signals and emergency flashers). Pull the stock ones out and push in the new ones (it is not that hard to align the terminals by feel, since it a bit hard to see the socket for one flasher).

John Durbetaki