Thought I would share my experience so if others wanted to try it they would have more info. I was able to piece together the info I needed but never really found details in one location.
Purchase:
MercMonitor Level 2 SmartCraft Gauge Kit. 79-8M0079865. Cost $576.00 w/ shipping on Ebay.
Mercruiser 25 Foot SmartCraft Wire Harness. 84-879982T25. Cost $80.19 w/ shipping on Ebay.
Mercruiser Male to Male Cable Assembly. 84-892452T01. Cost $15.74 w/ shipping on Ebay.
Total Cost: $671.93
Installation was straight forward.
1. Pull instrument cluster down. Remove the 8 each 1/8” Allen drive screws.
2. Remove speedometer. I taped up the light positive and negative connections just to make sure nothing could get shorted out. I inserted a nail into the pitot tube and wire tied with 2 wire ties to ensure no water would leak behind dash.
3. Pull fuze panel next to driver foot for access to run wires.
4. GPS wire harness was routed to the fuze panel so I created a new power wire and moved the harness to behind gauges where I could get to the NMEA 0183 connections. Yellow is Positive and Brown is Negative from the GPS (Raymarine RC-435 Chartplotter that is original to the boat). White with Blue stripe is Positive and Brown with White Strip is Negative from the MercMonitor wiring harness. I had a little connector so I used it to make easier if I ever needed to remove. You do have to go into the settings on the MercMonitor and change it to use GPS input.
5. Connected Temp Probe and wire tied to underside of dash. Did not want to drill a hole in the dash.
6. Ran engine harness down to behind fuze panel. Then ran to engine compartment.
7. Disconnected Cap on engine harness and plugged cable into engine.
8. Moved trim sender wire from Analog input to Digital input. You do have to calibrate the MercMonitor guage to the trim sender. As the book states, you need to do this while running. Get up on plane good. Calibration will have you trim full down and save, trim to up running position and save, then just save the trailer position without adjusting. Worked fine. I tried to calibrate a couple of times setting in the slip and it would never give me the correct settings. Full down would show 0 and full trim (not trailer) should show 10.
9. Tied everything up and installed dash and fuze panel.
I used the Male to Male Cable Assembly so I would not have to buy a junction box.
I did not connect an alarm, smart link, NMEA 2000, or anything else. All my gauges are analog.
Everything works great. Only thing that does not work is how much fuel is left in the tank as I don’t have a digital fuel sender (I could add one but it is no big deal to me). The gauge does indicate how much fuel has been used since the last reset.
My 278 is heavy w/ Radar Arch, 5 kw generator, 6.2L Merc engine, 85 gallons of fuel, 21 gallons of water, maybe 10 gallons in holding tank, all our stuff. I figure I am pushing 8500 lbs.
First test run, I always ran fully loaded like this at about 3700 rpms and 26 MPH w/ full up trim. Best I could estimate I was getting about 1.7 MPG. The gauge showed that I was getting 1.7 MPG at this speed/setting.
As I played I was able to get 2.1 MPG at 3850 RPM and 30 MPH and full trim. I would have never guessed that running that fast would give me better fuel economy. This was the best setting I could find. I am sure it will change a little as I burn off more fuel.
I was averaging 1.7 MPG and now getting 2.1 MPG. On a weekend trip of 250 miles round trip that is a savings of $100.00 based on our gas prices at the Marinas.
Bottom Line: I am very pleased and I am sure it will pay for itself over the next few years of use. Plus I love being able to monitor all the other engine readings.
Here are some pics but I can't seem to get them to show up here. Something about can't determine dimensions of image.
https://www.flickr.com/photos/129473286 ... 617349020/https://www.flickr.com/photos/129473286 ... 617349020/https://www.flickr.com/photos/129473286 ... 617349020/https://www.flickr.com/photos/129473286 ... 617349020/
Login
FAQ
Search
