Best location to splice engine temp sensor

[nortstudio]

I recently installed the Vapor digital dash, and chose the kit that came with the small, tubular sensor that gets spliced into one of te two radiator hoses.

I'm wondering which would be the best hose to splice into to give me the most useful reading, the left or right?

Thanks in advance.

Scott

[DonTZ125]

They SHOULD (!) be pretty much equal, assuming you're firing on all four cylinders with a comparable mix.

[nortstudio]

Thanks don!

[gre3nskeeper]

iirc, you should be able to unscrew the original temp sensor and install the vapor gauge one in its place. Just make sure you use copper anti seize on the threads.

[nortstudio]

Unfortunately, I got the type with the insert for the hose.

[thatkid]

Unscrew that one and screw it in to the stock housing.

[nortstudio]

Sorry kid, stock housing of what??? I'm not sure where the temp gauge gets its info from.

[gre3nskeeper]

#4

http://www.boats.net/parts/search/Yamah ... parts.html

this guy:

[nortstudio]

Thanks, that's what I found too - and hoped I was onto the right path. Can I use #5 on that fiche to splice the wires into?

Appreciate the help guys.

[nortstudio]

Hey folks. Finally getting back to the temp sensor for this Vapor dash.

I need a little clarification: in the photo greenskeeper provided, there is a circle around a part that looks like the one tucked into the Vapor in-line sensor, and then a pencil pointing to some wires.

I'm wondering if the suggestion is: A) snip the wires from the Vapor sensor and tie them into the circled unit, B) use the Vapor unit (that looks like #4 in the fiche) in place of the stock one or C) snip the wires from the Vapor sensor and tie them to wires that the pencil is pointing to.

Sorry for the tedious questions. Photo of Vapor sensor below.

[DonTZ125]

If you look past the wires to the brass hex-head part in the circle, that is the thermoSWITCH that turns on the fan; the pencil is pointing to the thermo UNIT (sending unit) that drives the temperature gauge, with its two push-on blade connectors. Either of those should be the same size as the Vapor unit, and either could be removed to install the Vapor sensor.

[nortstudio]

Thanks Don. If either can be removed and replaced, is there one that is preferable? What would be the differences in the two choices?

Appreciate the help.

[DonTZ125]

If you're replacing the gauges, wouldn't it make sense to replace the gauge sending unit? The switch is on-off, and has to remain installed - unless the Vapor has an output switch capable of driving the fan, at some selectable temperature?

[nortstudio]

The sending unit makes the most sense to me. I'll give that a shot.

Thanks

[olie05]

They SHOULD (!) be pretty much equal, assuming you're firing on all four cylinders with a comparable mix.

If you splice into the left radiator hose, you are measuring the temperature of water that has been cooled by the radiator. The right hose is the one that would give you a better estimate of engine temperature.

Also, the difference between the left and the right radiator hose temperature would not be affected by the number of cylinders that are firing. It is dependent on radiator inlet temperature wrt ambient air temperature, rate of flow of water through the radiator (RPM/ thermostat open/closed) and rate of flow of air over the radiator (relative air velocity, or fan on/off).

If you were to splice into the left radiator hose and your engine overheated, the gauge would only tell you that the engine was slightly warm.

edit: the difference between the left and right radiator hose temperature would also not be affected by mix.