new dash / control to engine harness needed for restoration

[trucknutz36582]

Hi -

I've decided to replace ALL the wiring in my 2003 Stingray MS 200 but i am not sure what to get
and have not had any luck searching for it. I will try to supply all the details, and I apologize if I ramble in the process.

It's a 2003 boat, currently with a factory new 4.3 engine ( SN 1A657529 )purchased last year.
When I saw a build date of 2011 I freaked out - However Mercury sales told me it was one of the last 4.3s that was built with a new block.



short version:
Can you tell me what part numbers I need to order to completely replace the existing wiring harness on the boat side?

Other details
the engine was purchased brand new last year and has all factory wiring intact,
but the mechanic moved the closed cooling system and its hoses from the old - 2003 4.3 engine to this new one.
a couple of sensors are not plugged in - including the coolant temp on top of the engine.
The vendor supplied the 10-14 pin harness adapter and the mechanic hooked it up to the old harness.

since the engine had been in storage for a year after it was purchased, and had a build date of 2011,
the mechanic removed the distributor and used an adapter tool to turn over the oil pump with a drill, so there is oil in all of
the galleys and the heads.

when I turn the key briefly the motor cranks over.
I leave it in the on position, but nothing shows on the SmartCraft gauge.
I have not connected the fuel yet - i dont want to start a brand new motor without having a way of seeing the oil pressure.

The Smartcraft gauge is an SC1000.
the extension cable is the blue smartcraft cable marked "resistor on this end" - on both ends.
I have tried it with and without the junction box
with and without an external terminator plug.

The Smart-Craft gauge does not display anything when the key is turned on - the volt meter moves from zero to 12, so the dash is getting voltage.

the SC 1000 back-light button does not do anything, so its not getting power at every pin
- is there a troubleshooting guide that show the proper voltage on each pin on the purple connectors?

I removed the yellow terminator on the port side front of the engine and plugged in there.
- is that the correct place to plug in? I could not see any other compatible connectors besides that one.

I have tried the left battery, the right , and both settings on the selector switch. Bilge pumps and lights operate normally, and
the engine does turn over. - I only turn it over a revolution or two to confirm that the starter is seeing the full amount of
voltage.

Wiring is 3- ought , so we are seeing the full 13.4 volts at the starter.


I have not added fuel yet - if the engine does not pump fuel and raise the pressure up to the injectors, will it not activate
the SC gauge?

I assume there are some safety interlocks as far as fuel pressure, oil pressure, and water temperature go , but I don't know what is absolutely required just to be able to "see" the ECU status on the gauge.

Parts used - are they correct?:


Mercury Smartcraft 878492K14 Boat Gauge Junction Box Kit
Mercury Mercruiser Quicksilver Oem Part # 84-879982B20 Harness-Bulk
Mercury Mercruiser Quicksilver Oem Part # 859318B 1 Terminator
this is to connect to Mercruiser 4.3 ECT serial number 1A657529

My theory is the old harness has a break somewhere, or too much resistance , or that the shop that
had my boat for 6 months without finishing it made some mistakes.

Its messy and complicated to rehab the old wiring, and I have had no luck finding a new shop in my area
so I am looking for a "plug and play solution" so I can get back on the water.
I would rather buy a new harness than pay for many hours of shop labor to trace and repair the old one.
ot to mention I prefer the simplicity of having everything of the same vintage - rather than mixing old and new.

in the last year I
had a shop repair the transom with new core
have replaced (with new)
engine serial number 1A657529
transom assembly (Mercury)
outdrive (SEI)
trim pump
batteries
perko battery selector switch
000 wires made by GenuineDealz.com
steering assembly and cables
hoses for power steering
steering ram
axles and springs on trailer
full set of new rims and tires

Now it needs new wiring - and yet another cleaning

Thanks in advance for your advice - you guys rock!

 

[alldodge]

Mercury Smartcraft 878492K14 Boat Gauge Junction Box Kit
Mercury Mercruiser Quicksilver Oem Part # 84-879982B20 Harness-Bulk
Mercury Mercruiser Quicksilver Oem Part # 859318B 1 Terminator

Going to need a few more parts then program the smartcraft gauge

Maybe we can get some input from Fun Times to assist also

 

[trucknutz36582]

thanks AllDodge -

does this mean that the 84-879982B20 harness is incorrect for a sterndrive boat?


this leads to another question -
I need a new warning buzzer, ignition switch and safety switch - what harness does Merc sell for these, or is this something I need to fabricate myself ?
I also want to replace the throttle / shift assembly and the wiring with it - i realized those parts are still old as well.

 

[alldodge]

does this mean that the 84-879982B20 harness is incorrect for a sterndrive boat?

Unable to say for sure, but it may very well be the next revision (newer one).

You have a lot of questions but for this old guy I need to work on only a 2 to 3 at a time.

Warning buzzer, just search Mercruiser warning buzzer and it will have a list

I also want to replace the throttle / shift assembly and the wiring with it - i realized those parts are still old as well.

There is nothing wrong with old stuff so long as it works. Many of the new stuff is not as good as te old stuff. If you really need to replace it, just do another search for Merc controls

 

[wellcraft-classic210]

Is your ground wire to the motor mount hooked UP ? That's the return from the gauges

Putting in a new harness can be a lot of work and have risks and costs of its own -- Might want to consider getting a competent electrical tech to help make an assessment. Could be something simple.



A simple and detailed description of whats not working might help us to walk you through the trouble shooting steps if that's of interest.

 

[trucknutz36582]

There is a 00 gauge cable from the battery to the rear of the engine block - on the factory ground stud -
it sounds like you're saying there's an additional ground I need to find?

here's a picture of it

 

[alldodge]

I think wellcraft was talking about the smaller (maybe 10 awg) black wire that comes out of the motor wiring harness and also goes to the engine block. Look closer to the block in your pic, there appears to be 2 other ground lugs attached behind the nut on the same post. If so, one of them is your harness ground

 

[trucknutz36582]

wellcraft-classic210 -

If I could find a competent electrical Tech who did not have a 3 month backlog, I'd definitely invest a couple hundred bucks in using their expertise. instead, I'll spend a couple hundred on a wiring assembly , and muddle through.

To answer one of your questions: what i am trying to accomplish is to put this boat in the condition as if it had been built in the last couple of years, instead of 15 years ago.
if you look at my list of items replaced - you can see I've practically got a new boat, with the exception of the hull and tee-top at this point.
It has had a hard life, with roughly 1300 hours on the original powerplant, and at least 3 owners before me. somewhere along the line it was neglected, filled with saltwater and allowed to sit for extended periods of time with the drain plug still in .


Since farming out the work isn't an option, I'm going the DIY route once again.
I'd prefer to replace assemblies than splice bad wires , all electrical items at the same vintage as the engine, rather than using adapters . After all, there's visible corrosion on almost all of the old stuff




I hope that I can contribute something of use to the community,so here goes:


My wife bought Service Manual #43 for me for my birthday - it looks like most of my questions about pinouts and wire colors etc are answered here - I'll dig in to the existing rats nest one more time with this as a guide and let y'all know what I find . I'm guessing that the Canbus + wire is not connected or broken , because the old harness does have a couple of broken wires in it visible - pinkish white - what the heck?

looks like pages 4d-19 and 20 are a good start


No part numbers in the manual, but I came realize that I was using the wrong lingo in my searching -
tried again with a search term of "Mercruiser 14 pin keyswitch harness" in google and came up with this:

84-896537K20-quicksilver-boat-instrument-harness-assembly (20 feet) with Key
84-896537T20 for 20 foot harness only

i called Mercruiser support (920) 929-5200 and they confirmed it

also comes in 15,11, and 8 ft lengths

so for an 11 foot harness (without the switch) its 84-896537T11

OEM safety switch part numbers that are compatible with this assembly since i still have my old throttle / shift assembly at this point:

19674A05
19674A06

and if I decide i'm ready to replace it the 4500 series includes the kill switch-
8M0060783 4500 series -single engine console mount