Wireing harness nightmare

[Casagf66]

Hello again sailors,

So my next step in renovating my new 1989 jeanneau 42 voyage will be to start tackling the perkins prima 50 electrical problems. Fortunately the boats systems wiring is in good shape. This will give me more time to focus on the motors wiring . Here's what I am facing.

1. Engine stop is not working, I am aware of the relays in the back and i plan on testIngram them. My Problem is there are three relays in the back of the motor and I have to figure out which one is what.... any one have experience with this?

2. The starter doesn't like to behave. She doesn't start up regularly and some times I have had to hot wire the darn thing.... also i noticed the previous owner added a fourth relay that runs a power to the starter solenoid.... This confuses me and I'll have to dig deep to figure this one out I suppose.

5. The harness is in bad shape with wires that go no where and is looks to be badly corroded, should I just get a new harness one? Does anyone else know a good marine electrition.

4. I have never done wiring on a desiel motor, but I am a quick and eager leaner.


Well thanks in advance all.

 

[bawlmer]

5. The harness is in bad shape with wires that go no where and is looks to be badly corroded , should I just get a new one?

I would start here. A wiring diagram would be invaluable. I went through similar drama when I bought Mystic. I would also resist the urge to rip everything out. Instead do this circuit by circuit until you understand what everything does and where everything goes. It may be just one or more of the 25 year old switches that wore out.
The fact that your PO installed a relay is cause for concern as he may have tried to patch something that needed a proper repair. A diagram would help there as well. One caveat that I learned from experience. Make sure the diagram fits both the motor and panel. I was pulling my hair out until I found out I had a panel that required a different diagram. Just sayin.

 

[Casagf66]

Here are some pictures of the relays

 

[Jim 5757]

As far as reliable starting is concerned, in addition to having our own problems with our Universal M20, we have seen many postings regarding this issue AND a service bulletin from Universal addressing this problem. You say the PO added a solenoid? Undoubtedly this was an attempt to remove the excessive voltage drop between the battery and the starter relay. For example, the original setup on our Universal had the ammeter, over 15 feet of 10-gauge wire, a car-type trailer connector, and an inline glass fuse in the starter circuit. Together, all of these added up to over 3-volt drop at the starter solenoid. If the battery was anything less than full charge, starting was hit-or miss at best. Once we upgraded the wire to 8 AWG, changed from ammeter to voltmeter, changed to a heavy-duty Blue Seas Systems MAXI Fuse Block, and upgraded the engine wiring harness with Anderson Powerpole connectors, voltage drop during engine cranking is less than 1-volt and reliable start is assured.

 

[capta]

Dollars to donuts you have a bad ground somewhere. That's where I'd start. Don't just look at them, take the lugs off and recrimp, cleaning the mating surfaces thoroughly before reassembly.
You didn't mention what motor you have.

 

[Casagf66]

It is a perkins m50

I agree, I will have to do a complete check and cleaning of all contacts.

I guess i will start on one system first and work my way around...

 

[Casagf66]

They have added a relay not a selinoid.

 

[Ted]

I know of a very good marine electrician located on the south shore of Long Island. I'm assuming that you're in Northport, NY and not another state. Send me a private message if you would like his contact information.