electrical meltdown 75 hp mariner (1987)

[Andre]

I am new to the mariner motors so I'll need some assistance with this electrical burnout that I discovered on a motor I am considering to buy. The trim is associated with this component as it's not fuctioning (only clicks).

Is this a rely or voltage regulator of some sort?

Is there a site where I can see the part fiche?

Here is a picture of the item in question.

 

[emckelvy]

Re: electrical meltdown 75 hp mariner (1987)

Hard to tell from the picture but it looks like it may be the rectifier. If so, this would have nothing to do with the power tilt motor problem.

You can easily replace the rectifier but I'd be really concerned about why it melted like that in the first place. That is not a typical failure. I'd really really be worried about the stator windings since they are known to have issues and you've had a major electrical fault with the melted rectifier.

If this motor is not running I'd be real wary. If it is running it needs to be checked out thoroughly and even then assume that you may have issues with the electronics sometime down the line; price accordingly.

On the PT&T problem, it's very common to have a bad solenoid. You can short across the main terminals of the solenoid to see if the PT&T motor runs. If not, the motor's got issues. Caution: watch for sparks when shorting across the solenoid, you don't want to spark a fire and melt something else!

You can look up parts for your motor here at iboat, for comprehensive parts diagrams go to this site, where they're organized by HP then Serial #:

http://www.mercruiserparts.com/SelectModelType3.asp?class_id=2

HTH...........ed

 

[j_martin]

Re: electrical meltdown 75 hp mariner (1987)

Usually it takes a battery installed backwards to do that. I'd be concerned about the oil alert malfunctioning also.

 

[Andre]

Re: electrical meltdown 75 hp mariner (1987)

Thanks guys for the quick response. Yeah, it's definately the rectifier assembly that was fried. one of the terminals was totally cooked and the cover took a bit of melting on the edge. A few of the other wires sustained some heat damage but I suppose those can be replaced and shrink wrapped.

The battery connected backwards probably makes the most sence but the level of damaged caused by this careless act is significant.

I checked the other fuses and they all look good although the boots took a bit of heat damage.

The good news on my part is I can renegociate the deal with the guy and get the motor knocked down from $500.00 to say $150.00 depending on what the repair costs are. He told me the motor ran fine when he last had it out (4 years ago) but during that time he had it sit (winterized) and left a bit exposed to the elements.

The boat it garbage but the motor looks like it's still in good physical condition. He's motivated to get it off his property so this will work in my favour for sure.

For now, I leave it as-is until we connect up again in the spring 2010.

Thanks again
Andre