coincidental problems
 

installed new tach today ,no problem,then went to take boat out for ride and engine shut off after about 5 minutes of running towed back to dock and found the fuse labeled 'engine 'was blown,replaced fuse engine started but afraid to take boat out for another run because not sure why fuse blew the first time?(dont want to get stuck on lake for second time in one day),also now the drive will not trim up,but works in trailer mode.anything that i could have done while changing out tack that may have effected fuse?will a fuse blow due to age,original fuses