how can i get the trip button on my steering wheel to work with aftermarket radio. i think i read somewhere that you could just ground a wire to make it work

 

The trip button??? what do you want that to control, i havnt heard of anything like that...

 

the trip button is not for your stereo it is for your odometer, you prolly mean the volume buttons

 

ok, now the real answer....

there are quite a few harnesses in your center console, behind your radio. 2 of the harnesses have a brown wire with white stripe. 1 of them is the correct wire.
i'll start off with 1 of the brown/white wires is for the trip button and the other is....your negative terminal for your front left speaker. few ways of figuring out which is the correct one.

1) 1 is thinner than the other. MUCH. you want the thinner one.

2) if you have the aftermarket radio wired into the speakers (i.e. no amp) then you can prolly already notice that the harness with the thicker brown/white wire is connected. that's cause it's your left speaker, so you've plugged it in (duh)

ok, so you found the thin brown wire with white strip, on a harness that is connected to nothing. snip the wire and take the cut end and ground it somewhere. ANYWHERE, but just ground it. close up, clean up, trip will work for good from now on. obviously your volume controls won't work, but if you want that to work, go back to the same harness and tap the PAC SWI-X module onto it. you then place the led wire somwhere visually seen by the aftermarket radio and it acts as a universal remote. program the buttons and your volume/mode/track change buttons will work.