Moderated Discussion Areas
  ContinuousWave: Small Boat Electrical
  Mercury FOURSTROKE Trim Gauge Installation

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   Mercury FOURSTROKE Trim Gauge Installation
seaboss19b posted 04-24-2008 06:01 PM ET (US)   Profile for seaboss19b   Send Email to seaboss19b  
I have a [here a model year was mentioned but by that year, Mercury Marine had abandoned the use of model year designators] Mercury 115 [here the term "four stroke" was used, but Mercury calls their motors that use a four-cycle combustion cycle "FOURSTROKE"] motor that I'd like to install a trim gauge. My dealer, 60 miles away, says it is a no-brainer. Well, I crawled under my center console and looked for the wires he described, but couldn't find them in the bundle coming out of the throttle control box.
I did see a red, blue and green wire coming from the tril/trim switch. Are tese the wires I should use or do I need to keep looking for the wires specifically designated for the meter?

Any help would be greatly appreciated,

jimh posted 04-24-2008 11:20 PM ET (US)     Profile for jimh  Send Email to jimh     
Get the schematic diagram for the circuitry you are trying to install.
seaboss19b posted 04-25-2008 06:04 AM ET (US)     Profile for seaboss19b  Send Email to seaboss19b     
I have a Teleflex trim gage and the schematic they provided is almost useless. I've also looked online for
the schematic for the power trim circuitry, but haven't run across one for late model 4-strokes. I know this is a simple install, I just need to find the right wires to connect.
swist posted 04-25-2008 08:35 AM ET (US)     Profile for swist  Send Email to swist     
In the 2004 version of that motor, the wire is brown/white (you only need one). It may be taped or tiewrapped to the bundle in the console such that it is hard to find, do some more poking - you may have to unwrap the bundle a bit and then re-tiewrap it when you find it.

The other end of wire is inside the engine cowling at the rear just behind where the rigging hose goes in.

The gauge sender on mine just screwed into pretapped holes that were already in the engine transom bracket. Two wires come out of the sender pot - one goes to ground under one of the mounting screws, the other you run up to the engine through the rigging hose gland. It's basically plug-and-play!

It took me about an hour to install my gauge, and 45 minutes of that was cutting the hole and dealing with the not-so-great rats nest of wires behind the instrument panel, with little slack and very tight working room.

Note this is not exactly the same engine, and changes may have been made in recent years. Jim's advice to find a wiring diagram is the way to go.

GreatBayNH posted 04-25-2008 10:21 AM ET (US)     Profile for GreatBayNH  Send Email to GreatBayNH back up what swist said.

seaboss19b posted 04-25-2008 03:42 PM ET (US)     Profile for seaboss19b  Send Email to seaboss19b     
Thanks for the quick response. I don't want to offend anyone who's tried to help me,but I think there may be sone specific information that I need. I have two wires coming out of the throttle control box, one red & yellow and the other red. I hav one wire coming out of the trim sensor, solid black wiht a white stripe. I can't seem to find the link between the two. I appreciate all the infomation so far, but I really need 2007 specific, 115 ho, 4-stroke info0rmation. I'm not a dunderhead, just new to boating electrics. Please don't be offended with my response.



GreatBayNH posted 04-25-2008 04:14 PM ET (US)     Profile for GreatBayNH  Send Email to GreatBayNH     
1) Did you purchase the trim sensor with the trim gauge or does that model Mercury engine have it built in?
2) What model Boston Whaler do you have?

I can only speak to the 2006 Montauk 170 with 90HP FourStroke EFI YamaMerc. I had to purchase the sensor and gauge (2 parts). The brown wire with white stripe (that connects sensor at transom to gauge at console) was pre-run at the factory. plug and play!

davej14 posted 04-25-2008 04:24 PM ET (US)     Profile for davej14  Send Email to davej14     
Ditto GreatBayNH.

I also had an unused brown wire with white stripe and it was plug and play. Any unused wire that will interconnect the sensor at the motor to the gage will work, there is no current load of consequence. Just use what you have and put a label on it for future reference.

Casco Bay Outrage posted 04-25-2008 08:19 PM ET (US)     Profile for Casco Bay Outrage  Send Email to Casco Bay Outrage     
Bruce -

I looked at the trim gauge installation instructions PDF on the Teleflex site and the document really sucks.

Have you tried emailing Teleflex customer support?

From their page page=1012 Send an email to [email][/url]

For everyone's benefit, what were the instructions your dealer gave you (in original post)?

swist posted 04-26-2008 07:45 AM ET (US)     Profile for swist  Send Email to swist     
Seaboss - I think there is some confusion here. If I am reading you correctly, you are talking about wires that come out of the console control box. The tilt/trim switch on the control has absolutely nothing to do with the tilt/trim gauge. The switch controls the motor that moves the transom bracket. The sensor reads the position of that bracket and sends it back to the gauge. There is only one wire involved. (The return loop from sensor to gauge is via ground). The other mounting posts on the gauge are for lighting, power, and ground. (Power usually comes from a purple wire you see strung between the gauges - it is only hot when the ignition is on so the gauges won't drain juice when the engine is off.
jimh posted 04-26-2008 09:24 AM ET (US)     Profile for jimh  Send Email to jimh     
Mercury has a couple of different motors they call the 115 FOURSTROKE. One power head was made by Yamaha and the other was made by Mercury themselves. However, in either case, I suspect that they used their own electrical harness, and they may have used the same mounting and tilt system. But it helps us to determine which motor you have if you mention it as being either the Yamaha-Mercury motor or the petite Verado or Veradito motor, which is the all-Mercury motor. Yes, I know this is somewhat awkward, but since the official name for both motors is 115 FOURSTROKE, it does not help us resolve the ambiguity about which motor you have. After 2006 there are no model years used with regard to Mercury outboard motors, so you cannot identify the motor by inventing a model year for it.

As mentioned, in conventional gauge rigging there are usually three circuits which are strung among the gauges in common:

--VIOLET is the +12 Volt DC battery via the ignition switch

--BLACK is the battery negative

--LT BLUE or BLUE is the gauge illumination circuit, usually via a panel switch

A trim gauge will have one and maybe two additional circuits.

--WHITE with TAN is the sender to gauge circuit, all have this circuit

--BLACK with TAN is the sender isolated ground, if used.

If the motor did not come with a trim gauge, it may not have a trim sensor. There may be a wire in the electrical harness for use with the trim gauge and the trim sensor. If there is not, it usually is not too difficult to add a wire, although you will have some trouble buying a small length of wire with WHITE with TAN insulation to install.

seaboss19b posted 04-27-2008 02:28 PM ET (US)     Profile for seaboss19b  Send Email to seaboss19b     
Well, I got it figured out and working. I'd like to thank all of you thant responded to my distress call. jimh really set me on track. I wasn't aware that there were two different types of Merc 115 hp 4-strokes. I have the Yamaha/Mercury version and everthing was right where you said it would be. I did have to dig deep in the wiring harness, but found the right wires, did as I was told and viola, the trim gauge works perfectly.

Thanks Again for everyones input.


mikemdd posted 04-29-2008 09:48 PM ET (US)     Profile for mikemdd    

How were the wires terminated on each end? Just loose in the bundle? I assume they were not connected to anything? Were there any labels on the wires?


Post New Topic  Post Reply
Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.