donzi matt

iTrader: (1)

I am going to replace all the gauges on my Cafe soon. My plan is to utilize the smartcraft capabilities of the motors, which are 2006 496 mag HO's. I am not quite sure on some details, so I thought I would ask some questions.

1) Do I need to run separate data lines from each motor to the helm? Or do I daisy chain from one motor to the other and then run a single data cable that communicates to both motors.

2) By connecting the fuel level senders as inputs to the master tachs I should be able to get the fuel use features of smartcraft, correct?

3) Can I add oil temp senders to my engines, connect them to the ECM, and use smartcraft gauges or do I need to use analog gauges for oil temp?

4) Any other potential pitfalls or problems that I may run into? I am working with Bill at Diamond Performance about a gauge package and will be using Livorsi gauges. I need to find out what Merc. part numbers I need for the communication harness from the motors to the helm and what junction box I will need to plug the guages into.

Thanks for any advice.

mdwstinger

I installed a 2004 496 ho package in my 1987 260 stinger. I redid the dash with smartcraft gauges. I have the speedo , tach , water temp, oil temp, water pressure, oil pressure, fuel, trim and volt. best investment on that boat.

1) You will need 2 engine harnesses 84-879968T-6, they connect into a rear mounted junction box 878492-4, that connects to a harness 84-879968-(6,10,15,20,30) which runs to the dash , connects to another junction box 878492-6 dash mounted, and then your gauge harnesses. 1 to the speedo, 1 to each tach, and then your other gauges link together off each tach. I have wiring for smartcraft gauge merc # 90-879939.

2) Yes , I get mpg, total fuel used , you can also calibrate your fuel gauges to how many gallons you actually have in the tank. But you need the harness from fuel tank to engine.

3) The engines already have oil temp sensors hooked to the pcm555 computer.

If you have any other questions , I would be happy to help if I can. It's very easy to do .

donzi matt

iTrader: (1)

I was under the impression from posts by Raylar and from the link below that the 496 doesn't monitor oil temperature. You are saying yours do?

https://mercurymarine-gsdesign1.netd...ity_charts.pdf

If you scroll down to the bottom it shows the HP motors have an oil temp option but the 496 does not.

I was thinking I can use my existing wiring to my fuel level senders at the helm and use that as an analog input to the master tach for fuel level. Will that work or will I need a specific harness to go to the engines?

Thank you for the information on the harnesses and junction boxes.

Mbam

Unless the engine harness has an oil temp connection you will not be able to read it on your smartcraft gauges. The PCM on the engine is what actually handles the analog to digital conversion from the sender and outputs the data to the can bus so the smartcraft gauges can display it. Make sense?

mdwstinger

I think you might be right on the oil temp. I've got the gauge hooked up and I thought that was working and just not getting to hot. I was looking at my accessories catalog and shows a oil temp sensor (to be) no price. I'm going to check into that. As far as fuel ,there is a specific harness that plugs into a connector on the top of the engine and to the sender. I was using a 2 terminal sensor ( probe) and my fuel gauge whould read only 3/4 tank when full, but read correctly when the fuel got to 3/4 tank
, Livorsi said i needed a 3 terminal sender, that didn't fix it,so I just been living with it. I also hooked up a depth sender that also plugged into the engine. you will also need termination resistor 859318T-2 at each junction box. If you want I could email you the wiring diagram and other info I have.