Serial number 6431959, 1983 mercury 150.
Ok my outboard will tilt/trim ok when you unplug the battery charger and the first time or two that I use it on the water. After that it doesn't want to trim up to lift the bow, it gets worse as the day wears on. At best it moves very slow. When I load the boat on to the trailer and I lower the motor on to the transom saver it will stop then after waiting for a minute or so it will lower some more but will raise ok. There are four switchez to tilt and trim the motor one at the back of the boat (add on I believe as it is an old school looking togle switch), the controller handle, aftermarket two button on the steering wheel and one at the bow. Starting noticing issues when using the one at the back of the boat a while back while the one on the controller, shifter worked fine but now it doesn't matter which switch I use. The one on the steering wheel doesn't work at all now.
So does this sound like I have an electrical problem or corrosion in the wiring? Been working a lot lately and most of my off days have been filled with chores or rain but I'm off for a few days this week and can look at it. When I pull the p, astic dipstick out it shows full for the oil reservoir.
Thanks for any help.