Try this: It may not work or cause problems.
Using above diagram.
Disconnect R18 & R17 ( Remove )
Leave R19 & R16 ( or cut in half or double value )
And either short or cut ohm's for R20 & 21
The problem is you dont want too much base current or will fry the transistors.
Now is the + voltage comming strait from the battery or through another resistor?
Both R18 & R17 are biasing the transistor and not letting it fully switch.
Tnks Dayfall for the part number.
PS: Dayfall. Have you try a cobo of P-Channel on top and N-Channel on the bottom?