Temp gauge mod......

[inamaze]

on my ex500 streetfighter build,

I put an Acewell digital gauge on it to give me tach, speedo, indicator lights...
But I also want temp...

the stock temp gauge is analog, and I have two ideas on changing it to an indicator light or lights.

First if I knew the voltage profile of the gauge (what voltage related to what temperature) then I could set up two LEDs to come on for a normal and high temp range.

Or, I could just go with a single LED for the high end of the gauge...as a warning it's overheating or about to.

Anyone done this kind of mod, or have any data on the voltage profile of the temp sensor?

thanks

[love2ride]

what about this one Auto Meter

[inamaze]

Not bad, but it's pretty big for just being a temp gauge. I'm trying to go minimalist, my Acewell is about that size but has tach, speedo, trip, time, 6 indicator lights, and some other stuff I haven't even figure out yet...

[inamaze]

So it's not actually a voltage profile I'm looking for... it's a resistance profile.

At warm, the sensor is around 175 ohms, and cools down to 220 ohms in a 10 min or so. Not sure where it's at when it reaches room temp...

[inamaze]

Ok well some progress, some data...

I took the stock gauge and hooked up 12 volts to it, then ran a variable resistor instead of the coolant temp sensor.

Mapped out the resistance values for the range on the gauge.

Bottom of the range the line at the C: 358 ohm
the next line up: 159 ohm
halfway within the cold range (bewteen the 2nd and third mark): 79 ohm
3/4 the way between 2nd and 3rd mark: 56 ohm
third mark: 39 ohm
first mark in the red range: 32 ohm
midway into the red range: 20 ohm
on the H mark (problems are near) 10 ohm

note also that variances in voltage to the gague (on the bike this would be battery and alternator supply voltages) will change the gauge needle position, but a variance of 1.5 volts is equal to a very small move on the needle, so you wouldn't mistake cold for hot if your battery was slightly low...

Again, I want a small temp indicator. While many say why bother, the machine has a cooling system and I want to know its health while it's running...

So I'm thinking of a small light bar and a circuit to indicate these temp positions, very compact and fairly simple to build. In the mean time I'll prob just rig something up quick and dirty to let me know when I'm approaching the hot zone.

If the above resistance map doesn't make sense and anyone actually gives a rat's a$$, I can post a pic that shows it better.

[zakman]

Try Dennis Kirk catalogue for a Shindy Products digital gauge about $90.00 its pretty small 2 wire hook up w/sender.