If I press G I can get the touchmaster to work, but how do I do like the manual press, and my priority? I can only get manu and a 1 second wail when I turn it on. Also how to use the horn when not on? If i hold down G it just cycles through them all rapidly. Thanks!

You need to change the siren keybinding in ELS.ini, it is interfering with the normal use of the G key. After you change the ELS siren keybinding you can manually toggle by either using the ELS siren key (cars won't pull over) or by pressing and holding G like usual.

Where do I do that?

ELS.ini

Togglesiren=###

the key codes are listed down the page

ELS.ini will be found in your main GTA folder, the same place as the Common, PC and Scripts folders. Open it with a text editor and refer to the key code list on the bottom to change the key for the siren. I have mine set to one of the numpad keys. You'll then be able to use the siren like normal.

If you dont see a .ini it will be the ELS file with a note with a cog/gear icon

OH! Okay, got it! Thanks!