50HP Merc 4 stroke electrical problem

[jh824]

I have a 1998 50HP Merc 4 stroke (not EFI)on a 17foot LEGEND (Aluminum) boat. While out cruising I noticed my gauges (Tach,fuel,battery) fluctuate but I didn't lose power. I docked and when I tried to restart, I had no power (the gauges usually react when I turn the key). No clicks, no sounds, no nothing. The trim on the gear shift won't work either.<br />The funny thing is my am/fm radio, fish finder and trim using the switch on the engine still work. I know it is an electrical problem, but am looking for some advice as to what to look for.

 

[WillyBWright]

Re: 50HP Merc 4 stroke electrical problem

Welcome to iboats and your problem is at the battery, or you blew a fuse on the motor.<br /><br />First, check the battery connections. They have to be clean and tight. Wingnuts are the biggest mistake a battery manufacturer can make when it comes to the motor they complement. They give the owner the illusion that they can just twist them with their fingers and that's enough. NOT!!! Grab a pliers and crank them down.<br /><br />Then check the fuse under the hood. It may be blown. The boat systems are separate from the motor systems. They meet at the gauges and that's where your problem is showing. The boat systems have one (or more) fuse and the motor has another (or more). Both have to be good for the gauges to work properly. The motor fuse controls the gauge function. The boat systems fuse controls the backlights.

 

[BillP]

Re: 50HP Merc 4 stroke electrical problem

I have a 1996 Mariner 50 4 stroke which is a merc in different colors. When near new it was acting up the same as yours. I found the problem to be at the large round electrical harness connector mounted on the back of the block. The male pins are rolled hollow and weren't making good connection until I spread them for a tighter fit. Check that connector and see if yours are same. My problem went away and hasn't come back since...that was 5-6 yrs ago.

 

[jh824]

Re: 50HP Merc 4 stroke electrical problem

Thanks for the suggestions. I forgot to mention in my original submission that all the fuses were checked and found to be good. I will double check the wingnuts and the electrical harness. If you can think of any other suggestions please let me know.<br />Thanks agan.