Problem with Smart craft on Mercruiser engines

[yoohan909]

I bought a 2005 Sea Ray 300 Sundancer two years ago with twin Mercruiser 5.0 MPI. It was a hurricane Sandy salvage boat. It had taken in water in engine room. We took out the engines and rebuilt them. We also installed new ECM:s on both engines.

After putting back engines boat ran perfectly on sea trial apart from that all the smartcraft gauges was completely dead on both engines. When turning on power you can see a slight move on the needles so they are getting some kind of electrical current. The helm was never under water.

We had a Mercruiser mechanic programming the engines for us and assigning them as master/slave. Still dead gauges.

We replaced the junction box and the cables between the junction box and the ECM:s with new ones. Still no difference.

We bought this kit:

(1) Mercury SC1000 Systems monitor part # 79-879896K10
(1) Tachometer cable assembly part # 84-879979A1
(1) Junction Box Kit part # 878492K14

With the kit we could simulate a signal to the gauges. The gauges then appears to show correct values. But when we connct Smartcraft gauges to the ECM:s through the junction boat, they are dead.

We are stuck in error searching.

Any ideas on how we can get the smartcraft gauges to work?

 

[alldodge]

I bought a 2005 Sea Ray 300 Sundancer two years ago with twin Mercruiser 5.0 MPI. It was a hurricane Sandy salvage boat. It had taken in water in engine room. We took out the engines and rebuilt them. We also installed new ECM:s on both engines.

After putting back engines boat ran perfectly on sea trial apart from that all the smartcraft gauges was completely dead on both engines. When turning on power you can see a slight move on the needles so they are getting some kind of electrical current. The helm was never under water.

We had a Mercruiser mechanic programming the engines for us and assigning them as master/slave. Still dead gauges.

We replaced the junction box and the cables between the junction box and the ECM:s with new ones. Still no difference.

We bought this kit:

(1) Mercury SC1000 Systems monitor part # 79-879896K10
(1) Tachometer cable assembly part # 84-879979A1
(1) Junction Box Kit part # 878492K14

With the kit we could simulate a signal to the gauges. The gauges then appears to show correct values. But when we connct Smartcraft gauges to the ECM:s through the junction boat, they are dead.

We are stuck in error searching.

Any ideas on how we can get the smartcraft gauges to work?

:welcome: to iboats

My guess is you have issues with salt water inside the harness. Salt gets inside all wiring and will destroy it. The original ECM's are sealed so they may have been OK, but you replaced which is good and takes them out of the equation. You either need to replace the engine harness or take the harness apart, clean, ring out each wire and rebuild.

 

[Fun Times]

When the Merc service tech had the Mercruiser Computer Diagnostic System connected to the engine, did they try using the CDS to test the original tachometer gauge feature to activate the gauge for about 10 seconds for gauge testing between the ECM and gauge?

Are you connecting this new monitor along with other analog or digital style gauges with needles?

Check your fuse as well like mentioned here by David, http://www.thehulltruth.com/marine-...martcraft-problem-merc-twin-installation.html

AllDodge has you heading in the right direction. Typically it's recommended to replace the engine wiring harnesses after being submerged like that...New harnesses are normally factored into the boat insurance costs when either totaling out or repairing a boat to avoid future electrical running problems.