2003 Silverado 1500 Trailer Lights

I need some help... I have a 2003 Silverado Ext Cab. I have removed the 7 pin Trailer light adaptor and replaced it with the standard 4 pin flat plug. When I hooked up the trailer the lights do not work correctly. When you use the turn signals both of them pulse. When you hit the brakes they turn off completly. So I wired them straight from the turn lights themselves and I still get the problem.. I know I am missing something here.. The manual of course did not have any info on this. Can someone fill me in here ??

this is a little late but they sell an adapter to go from the 7 pin to the 4

these are the colors for my 2k should be the same
wire colors off 7 pin
4 you need for 4 pin
white = ground
dark green = right turn stop
yellow = left turn stop
brown = running park
others
light green = backup
dark blue = trailer feed
red = battery
sorry about all the help i can give you, good luck

when both lights flash when 1 signal os on and it goes out when you hit the brakes it means you do not have a good ground . check your wiring again and make sure that the ground is good and clean.

when both lights flash when 1 signal os on and it goes out when you hit the brakes it means you do not have a good ground . check your wiring again and make sure that the ground is good and clean.

The weird thing is the book and others have told me that white is ground. However there is not a white wire.. not sure if it was miss wired from the dealer and it may be another color.

I had almost the samething happen to me, except I didn't change anything. One day hooked up my trailer and weird things happened. Spent hours troubleshooting and it turned out my flasher/turn signal relay was bad. Installed an heavy duty flasher and worked fine. funny thing was that without the trailer hooked up all was fine.

sometimes the ground wire is coloured black

Best thing to do is go to the place you got the flat four pin connector and ask them why they didn't just sell you the adaptor. Them tell them you want the four pin connector harness for your truck. The harness plugs right into the conector on the wiring harness on your truck. It is a five minute job and you do not have to splice anything. Also white is your ground.