Re: 1985 mercruiser 120/140 will not trim up
If the trailer button works, could be your trim limit switch. Take a look at the wiring diagram (page 6-10 from above). 16 is your trim limit switch, find the wires coming from that switch (back of boat) unplug them and jumper between the p/w and b/w wires. see if trim up works. If it does your trim limit switch is not working (common problem). Good luck.