Yamaha digital to analog gauge conversion

[skyviper]

Hi boaters, I'm looking for some info on how to convert from my non-working Yamaha digital gauges to an analog setup. I have a 2004 115tlrc 2stroke motor. The replacement Yamaha gauges are way out of my budget so I was wanting to switch to some analog ones. I'm wanting to have the following setup; tach, voltage, hour, fuel, trim and if possible water temp. I known the stock setup uses a warning indicator for water and oil problems but if I can convert that to gauges or indicators I'd like to. I'm not concerned with a speedo since the previos owner cut the sender line and my gps tracks speed. Any input is greatly appreciated.

Thanks,
Sky

 

[Silvertip]

Re: Yamaha digital to analog gauge conversion

Buy the gauges you want making sure they are for a two stroke engine. There is no conventional "oil" gauge for a two stroke but you can buy a Water Temp and Water Pressure gauge. Every gauge requires +12 volts with key on and ground to operate. The fuel gauge, temperature, tach and trim gauges all require senders that match the gauge. The gauges also have an internal light that gets wired to the NAV position on the NAV/ANC switch. Here is a diagram

 

[skyviper]

Re: Yamaha digital to analog gauge conversion

Ok so there isn't anything special I need to wire the analog gauges to work? I'm only asking because I was looking for this info on the Yamaha Outboard site and all I could find was info on the digital gauges and special harnesses needed. Was making sure there wasn't anything special I would need to get for converting over to analog gauges. Thanks for the reply Silvertip, I was actually hoping to get a response from you as I've seen you are a well of knowledge.

By chance, my manual doesn't tell me what wires are for the water temp or pressure, do you know which ones they are?

 

[Silvertip]

Re: Yamaha digital to analog gauge conversion

A water PRESSURE gauge does not need a sender. It works just like the speedometer -- on water pressure compressing air in a tube that works the gauge. You need to tap that tube into the cooling system on the engine -- like this (although this is a Merc):

Did you have a water TEMP readout before? If so, the wire on the temp sender on the engine is what you are looking for. If not, you need to add the sender and use whatever color wire you like.

No - I do not have the wire colors as hand.

Your new gauges will likely have threaded posts that accept ring terminals. If your existing gauge connections were plug-in types, you will need to remove the plug and add ring terminals to the appropriate wires.

 

[skyviper]

Re: Yamaha digital to analog gauge conversion

No water TEMP, on my motor is a thermo switch that just has an on/off state to indicate a overheat condition that is relayed to an indicator lamp on my digital gauge.

I'll have to crawl under the dash tomorrow when I go out to install the new bilge pump, fuel hose and livewell hose to see what kind of connections are already existing. If I have to change them that's fine, I have all the connectors in my toolbox already.

 

[skyviper]

Re: Yamaha digital to analog gauge conversion

Another question about installing the TEMP gauge to my motor. I found out I have to install a temp sender unit for the gauge etc. Only problem is I don't know where I'm supposed to install it so I can find out what size sender unit to get. I've attached a couple images of my motor with possible locations, any input would be awesome.

 

[Silvertip]

Re: Yamaha digital to analog gauge conversion

I don't see any vacant threaded ports into which one would screw in a temp sender. However, many installations require the use of a "Z" bracket. One end of the bracket is secured to the engine with a head bolt. The other end of the bracket secures the temp sender into contact with the head. You want the sender located near the plug on the upper cylinder which should tend to be the hottest. Here are pictures of the screw in and contact type senders. The contact type are hard to find. The temp sender must have a resistance range of 33 to 240 ohms (hot to cold).

Contact type sender (technically a cylinder head temp sender)

Water temp sender (screw in type)