Mercmonitor Level 1 vs Level 2

[Puma]

Is there ANY difference in the information that's available on the gauges (not on the N2K network) between the L1 and L2 MercMonitors?

 

[Puma]

Oh, one more question. Any reason I can't just pop out my speedo (2006 260DA) and put the Mercmonitor in it's place? I assume the speedo has all the correct wiring behind it to hook up a Smartcraft gauge? Is it really as simple as "plug and pray"?

 

[bajturner]

The physical installation is very simple. As for the electrical connection, you have to make sure you buy the right harness. When I installed mine, the connector on the speedo was different than the one on the MercM. You remove the speedo and its harness back to the SmartCraft hub, then plug-in the new MercM harness. If you have an air temp sensor (or any other things that input specifically to the speedo), make sure to get the harness with the appropriate inputs.

 

[Puma]

How do I figure out what harness to buy? Seems that they are all just L1/L2/SmartTow, etc? Or do I just get the harness separate from everything else?

Here's a picture of the speedo that I want to replace:

http://www.searay-parts.com/Sea-Ray-Mercury-Smartcraft-gauge-p/smartcraft srlinkspeedo.htm

Any comments on the difference between the levels, is that only for the N2K information, or does a L2 gauge have more features than a L1 (internal to the gauge itself, not N2K).

The physical installation is very simple. As for the electrical connection, you have to make sure you buy the right harness. When I installed mine, the connector on the speedo was different than the one on the MercM. You remove the speedo and its harness back to the SmartCraft hub, then plug-in the new MercM harness. If you have an air temp sensor (or any other things that input specifically to the speedo), make sure to get the harness with the appropriate inputs.

 

[bajturner]

Here's a picture of the speedo that I want to replace:

http://www.searay-parts.com/Sea-Ray-Mercury-Smartcraft-gauge-p/smartcraft srlinkspeedo.htm

This changes things, actually. I wrongly assumed your speedo was a system speedometer. It is a system link speedometer so it's not a simple swap. System gauges plug into the SmartCraft bus, whereas system link gauges are slaved off of system gauges. The MercMonitor is a system gauge.

You have only one system gauge, the tach, with both the 4-in-1 gauge and the speedo slaved (daisy chained) from it, and the tach plugged directly into the SmartCraft bus with no hub (called a J-Box). You have nowhere to plug the MercMonitor in unless you get a J-Box. There are some on this page:

http://www.mercurypartsexpress.com/...ts&mode=search&q=j+box&search_by=sku&cat=3164


You should talk to Mercury and make sure you get the right J-Box, MercM harness, terminations, etc.

 

[66pony]

I installed a L2 in my speedometer space. I had to attach it to the SmartCraft hub. The biggest issue I had was getting an extension to complete the daisy chain of gages since I removed one in the chain.
I bought the Gage from a member that works for a Sea Ray dealership on the board, and they were extremely helpful and worked with me through the whole thing.

 

[bajturner]

...I had to attach it to the SmartCraft hub...The biggest issue I had was getting an extension to complete the daisy chain of gages since I removed one in the chain.

Did your boat already have a hub, or did you add one? The schematics for the single-engine boats with SmartCraft don't show a hub.

Regarding the daisy chain problem, did the harness that came with your MercM not have a system link port on it? It would have been possible to start a second chain at the MercM if it did. This is where getting the appropriate harness is important.

 

[Puma]

Ok, that makes sense. So I need to "split" the wire that comes up to the tach and take that over to the Mercmonitor (and NOT use the wire that comes from the tach to the speedo today).

Is this the Jbox you're referring to (link didn't work for me):

http://www.veradoclubparts.com/JUNCTION_BOX_KIT_p/87-8492k14.htm

So, looks like I'd take what's plugged into my tach today into this box, and then from this box out to the tach and the Mercmonitor? Seems pretty straighforward if that's the case.

The only final question; how do I figure out what wires I need? Or are they "universal"; IE, the wire that plugs into my system tach today will plug into one side of this, and then I'll just need 2 new wires to plug into the tach and the Mercmonitor?

This changes things, actually. I wrongly assumed your speedo was a system speedometer. It is a system link speedometer so it's not a simple swap. System gauges plug into the SmartCraft bus, whereas system link gauges are slaved off of system gauges. The MercMonitor is a system gauge.

You have only one system gauge, the tach, with both the 4-in-1 gauge and the speedo slaved (daisy chained) from it, and the tach plugged directly into the SmartCraft bus with no hub (called a J-Box). You have nowhere to plug the MercMonitor in unless you get a J-Box. There are some on this page:

http://www.mercurypartsexpress.com/...ts&mode=search&q=j+box&search_by=sku&cat=3164


You should talk to Mercury and make sure you get the right J-Box, MercM harness, terminations, etc.

 

[Puma]

Oh yeah, and the "easy" question still out there.. Does the L1 vs L2 of the Mercmonitor change anything on the gauge, or ONLY on the NEMA output?

 

[bajturner]

Oh yeah, and the "easy" question still out there.. Does the L1 vs L2 of the Mercmonitor change anything on the gauge, or ONLY on the NEMA output?

From everything I read when adding this gauge to my boat, there is no difference between the SmartCraft functionality of the L1 and L2 gauges. I am not positive about this...and a dealer may not know. Try to get a hold of someone at Merc.

Ok, that makes sense. So I need to "split" the wire that comes up to the tach and take that over to the Mercmonitor (and NOT use the wire that comes from the tach to the speedo today).

Is this the Jbox you're referring to (link didn't work for me):

http://www.veradoclubparts.com/JUNCTION_BOX_KIT_p/87-8492k14.htm

So, looks like I'd take what's plugged into my tach today into this box, and then from this box out to the tach and the Mercmonitor? Seems pretty straighforward if that's the case.

Yes, this is essentially what you are doing. Regarding the J-box, there are a number of different ones. Go to http://www.mercurypartsexpress.com/ca/ and do a search on "j-box", then click on the junction boxes link. There you will see a number of different junction boxes, including the following part numbers for 4-port J-boxes: 878492T14, 878492B14, 878492K14. The K includes two weather caps. It's not obvious what the difference is between the T and the B. You need caps for the unused ports.

The only final question; how do I figure out what wires I need? Or are they "universal"; IE, the wire that plugs into my system tach today will plug into one side of this, and then I'll just need 2 new wires to plug into the tach and the Mercmonitor?

You will need to talk to a dealer or Mercury for this. They seem somewhat universal, but there could be incompatibilities. For example, when you unplug your current system tach from the engine SmartCraft harness, they will be opposite gender. The J-box ports are all the same gender, so one of the two will not plug in. You will need to confirm what is needed here.

Another example: I had my first MercMonitor replaced under warranty (there was a firmware update) and the second one came with a different harness which included a thermometer input (which I needed, coincidentally). They both worked.

Also, there are DTS and non-DTS SmartCraft harnesses. I think DTS are 14-pin and non-DTS 10-pin. You need to talk to someone that really knows!

 

[66pony]

I wanted to keep all the gauges on one chain. Could have done two but wanted to leave on one chain for simplicity.
I did have a hub already mounted and it looks like the one you are referring to. There are no changes to the gauges just the NEMA input and output. Time and Location are shared with SmartCraft if you interface with your GPS. Makes the instruments complete. The best part is that I can have custom alarms for engine issues come across and display on my GPS monitor.
I have DTS. I do not know if that make s a difference

 

[Henry Boyd]

Ok, that makes sense. So I need to "split" the wire that comes up to the tach and take that over to the Mercmonitor (and NOT use the wire that comes from the tach to the speedo today).

Is this the Jbox you're referring to (link didn't work for me):

http://www.veradoclubparts.com/JUNCTION_BOX_KIT_p/87-8492k14.htm

So, looks like I'd take what's plugged into my tach today into this box, and then from this box out to the tach and the Mercmonitor? Seems pretty straighforward if that's the case.

The only final question; how do I figure out what wires I need? Or are they "universal"; IE, the wire that plugs into my system tach today will plug into one side of this, and then I'll just need 2 new wires to plug into the tach and the Mercmonitor?

Its pretty straight forward once you see the parts. The plug for your present speedo is a small four pin deal. The plug for the Merc monitor will be much larger (10 or 14 pins). That being said, the wire harness for the Merc Monitor will have a specific part number.

There is a possible complication. The main trunk segments of the SC network need to have terminating resistors at each end. These resistors are either built into the trunk cable (it will be marked), or they are installed in the junction box with a resistor cap. You need to determine what setup you have; either a junction box with resistor cap, or simply a trunk cable w/resistor feeding a single harness for the Tach that then has sub-leads to daisy chain the link gauges. If you have the former, there will only be one port open for the monitor harness, although two will be capped. Just make sure the resistor cap gets installed back on the box. If it is the latter, just get a junction box with weather caps DO NOT get resistor caps. Plug the existing trunk cable in and then plug the MM to another port. Cap the ends and you are done.

Here is a picture of the box I installed when I upgraded to SC:

This is a bit of a hybrid. My trunk cable has the resistors built in. When I started my upgrade I was given the cable, so I just worked from there. The point is that if you have the cable with resistors you can add the junction box.

Henry

 

[bajturner]

Here are some more pictures for you from Mercury parts express (worth 1000s of words, right?):

This should be similar to your current tach harness. It has 10-pin female ends and also a smaller system link connector (this is what your speedo plugs into now). This is either plugged directly into a 10-pin CAN plug on your DTS command harness, or to a junction box. As Henry pointed out, it will already be properly terminated either with a termination resistor in one of the ports of the junctrion box, or one that is integral to the CAN extension on the DTS harness.



This is a termination resistor that plugs into an empty port on the junction box if the CAN data harness does not have an integral one.



This is a weather cap that you would use to cap unused ports on a junction box. If you have a four-port junction box you will need one of these if you don't need a termination resistor, or none if you do need a termination resistor (Port 1: CAN harness, Port 2: system tach, Port 3: MercMonitor, Port 4: termination resistor or weather cap)



This is a female-to-female gender-bender adapter. You may need one of these if the end of the CAN data harness is male (seems unlikely) in order to plug it into the junction box, which is also male.



This is a male-to-male gender-bender adapter. If your system tach plugs directly into the CAN data harness (no junction box), there may alread be one of these being used to plug the female tach harness into a female CAN data harness. You would remove this and put the junction box in between instead.



You need to get under there and see what is already there. Again, watch out to get all the right part numbers. There are sometimes multiple versions of what appear to be the same thing.

Hopefully this is helpful,
Brian

 

[Puma]

Ok, here's the wiring diagram on my boat:

http://www.searay.com/boat_graphics/electronic_brochure/Company1729/1C1_23_74DEJAKXM8I.pdf

Page 106 shows the SC layout. Looks like the wire comes in from the engine to the tach (system gauge) and then over to the 4 in 1 and then finally to the Speedo. Appears that the terminators are on the cable (part number 879982B25, 2 terminator resistors). So, it appears that I need to pull the the cable that's on the system gauge (the tach) and run it into the "splitter". Then, from the splitter to the system link gauge and then to the MercMonitor.

Here's a link to the cable that I have:

http://www.ishopmarine.com/ebook/025/005/79

So, it seems that I need the JBox without termination? This part number: 878492K14.

Any other problems anyone sees? This looks pretty straight forward.

 

[bajturner]

So, it appears that I need to pull the the cable that's on the system gauge (the tach) and run it into the "splitter". Then, from the splitter to the system link gauge and then to the MercMonitor.

Sort of. Yes, you unplug the system tach and plug it into a junction box. No to the rest.

Here's maybe how it goes (I say maybe, because you may find what is actually in your boat does not match what is in your documentation):
- Unplug and remove the speedo system link gauge. If installed per the schematic, it is at the end of the the system link chain. If not, swap its position in the chain with the 4-in-1. Cap the remaining system link plug; there should be a cap on the speedo you removed that can be used.
- Mount the MercMonitor where the speedo was.
- Mount the junction box (what you call the "splitter", I think) in a relatively convenient location. Make sure it's not in a location where wires will interfere with the sliding cabin door.
- Unplug the harness from the back of the system tach and plug it into the junction box. Do not unplug the 4-in-1 gauge. The system link lead may not be long enough to reach once you move the connector from the tach to the j-box. Not a big deal if not, just unplug the 4-in-1 and move to the next step.
- Using a new system tach harness that you will have bought, plug one end into the tach and the other into the j-box. This harness will also have a system link lead. If you had to unplug the 4-in-1 in the previous step, use this system link lead to plug it back in. The system link lead on this new harness should have shipped with a weather cap on it. If you use this lead, reuse the cap on the original system link plug that you unplugged.
- Using a new MercMonitor harness that you will have bought, plug the appropriate ends into the MercM and the j-box (if I remember well the ends are different, and you can't get it wrong). This harness may also have a system link plug. It may also have an air temperature probe connection. It may also have the air temperature probe that you can install if you don't already have one. The part numbers of these harnesses are a bit of a mystery.
- Put a weather cap that either came with your j-box, or that you bought separately, on the last open port on the j-box.
- Read the manual that came with the MercMonitor. You will likely reread it a couple more times.

In theory, this is it...unless I missed something.

So, it seems that I need the JBox without termination? This part number: 878492K14.

Any other problems anyone sees? This looks pretty straight forward.

It looks like that is the right j-box, but I don't know what the difference is between the 878492B14, 878492T14, and 878492K14, other than the K has the weather caps. What is the difference between the B and the T? Is the K a B + weather caps or a T + weather caps. All the harnesses seem to have a B and T version. I would love to be educated as to the difference. The T versions are always a little more expensive. I see your existing harness is a B. Here is a possible bill of materials:

- 1 x MercMonitor L1: Call Mercury for the latest part number...these have been superceded frequently.
- 1 x MercMonitor harness: Mystery -> get this from Mercury too, including the different variations.
- 1 x System tach harness: 879979T11
- 1 x 4-port junction box: 878492B14
- 1 x SmartCraft weather cap: 859318B2

You are correct this is pretty straight forward if (IFF) you get all the right parts. The only other curve ball would be not finding what you expect when you take a look at the actual wiring.

 

[Puma]

Thank you so much for the great post, I hope others (and certainly I have) find this helpful as well!

I spoke with Merc, there is no difference between the B and T versions. The B is "bulk" (like what they sell to SeaRay) and the "T" is "single". The guy on the phone said "they are exactly the same thing". I suppose maybe they have different packaging (I didn't ask), but he was 100% certain that "they are the same cables".

The MercMonitor doesn't come with the harness? That's something I wasn't expecting, I figured it came with whatever was necessary to plug into the Jbox.

I wasn't thinking about the system tach cable, I see what you're saying though. Existing cable goes to the jbox, then the system tach cable goes from the jbox to the tach (and the Merc monitor harness goes from the jbox to the MM). That makes sense.

It looks like that is the right j-box, but I don't know what the difference is between the 878492B14, 878492T14, and 878492K14, other than the K has the weather caps. What is the difference between the B and the T? Is the K a B + weather caps or a T + weather caps. All the harnesses seem to have a B and T version. I would love to be educated as to the difference. The T versions are always a little more expensive. I see your existing harness is a B. Here is a possible bill of materials:

- 1 x MercMonitor L1: Call Mercury for the latest part number...these have been superceded frequently.
- 1 x MercMonitor harness: Mystery -> get this from Mercury too, including the different variations.
- 1 x System tach harness: 879979T11
- 1 x 4-port junction box: 878492B14
- 1 x SmartCraft weather cap: 859318B2

You are correct this is pretty straight forward if (IFF) you get all the right parts. The only other curve ball would be not finding what you expect when you take a look at the actual wiring.

 

[bajturner]

The B is "bulk" (like what they sell to SeaRay) and the "T" is "single". The guy on the phone said "they are exactly the same thing".

Excellent, thank you. The only new thing I learned today was from CSR!

The MercMonitor doesn't come with the harness? That's something I wasn't expecting, I figured it came with whatever was necessary to plug into the Jbox.

I not sure about this one to be honest. I bought one early-on when it was diffucult to even find the correct part number for the MercMonitor itself, and the harness was a separate part number (and difficult for the dealer to find). When Mercury sent an RMA to replace the first gauge, it was for the MercMonitor only, but they replaced it with a new gauge and a different (but similar) harness. Maybe try to confirm this with Merc as well. I know everywhere I see MercMonitors online they reference different part numbers...

 

[Puma]

Just wanted to update, got the following communication from Merc this morning:

"[FONT=&quot]79-8M0055120 comes with the MercMonitor Harness. This harness would attach to the back of the MercMonitor on one end and then to a junction box at the other end. Please see attached document for more detail."

Sounds like the above part number includes the harness. I'd still need the Jbox to tach connector, but, sounds like the kit has everything I need to come from the junction box out to the MM.
[/FONT]

 

[bajturner]

I'd still need the Jbox to tach connector, but, sounds like the kit has everything I need to come from the junction box out to the MM.

Great, so it looks like this is what you would need then:

- 1 x MercMonitor L1 w/ harness: 79-8M0055120
- 1 x System tach harness: 879979T11
- 1 x 4-port junction box: 878492T14
- 1 x SmartCraft weather cap: 859318T2

Buying the j-box with no caps (T version) and one cap seems to be less expensive than buying the K version which is the j-box with two caps (makes sense, I guess!).

Note if you don't have an air temp sensor and want to add one, you may be able to get a harness for the MM that includes it. If you already have one, it should plug in as before.

Double-check that you don't have a j-box already before ordering. It sounds like 66pony's boat has one even though I don't think the schematics show it.

 

[Puma]

After all these hard technical questions, this should be an easy one..

Where should I go to order all these parts? VeradoClub has the monitor, but not some of the cables. I'd like to get it all at once at a good price from a reputable dealer, any suggestions are welcome!