My starboard engine drops 300-600 rpms when the drive trim or trim tabs buttons are pushed running between 3000-5000 rpm under load, when button is released rpms kicks back up, Replaced coil, plugs, cap, rotor, distributor sensor module, cleaned all connections, (electrical not fuel) fuel system checks out OK.

Stumped?????

Anyone have any thoughts as to why when the trims are used something is causing an amp draw that knocks out the engine?
454 Mark IV, Thunderbolt IV Ignition
Thanks

It's seems like you should be blowing a fuse with that kind of draw . Is your trim pump motor going bad causing this ? Have you had someone put eyeballs on your tabs when activated to make sure they are functioning properly ? Grounds all tight and clean ? Just some thoughts .

Trim tabs / drive trim pumps working, trims go up / down, no fuses blown ???????????

i would check alternator connections and output, it may not be putting out.

sounds like drive trim and tabs are wired in with the motor. need a seperate hot to batt or batt switch for each circuit. also as deep said, check the grounds for them.

Thanks guys for all the suggestion's!

check your grounds and make sure you have ground cable run between the motors.

Grounds.
There's a missing/loose/corroded ground.
MC

I have taken every connection from the dash to the engines apart and SS wire brushed them, checked every wire for ohmmeter resistance - All checked out OK, checked Amp draw on all four trim motors - they all draw what the specs in manual #5 says (9 amps). Going to dip it tomorrow and see where I'm at with it.

Battery is probably going away. That serves as your voltage reservoir. Is the engine a little sugggish to crank?