instruments wiring question

[Spike16]

couple of questions

Iv got a new temp guage to put on the bike but the sender unit is much larger than the standard item, pritty sure its ment to go in the rad but u use the original wiring unlike the scitsu temp guage (ie put their sender in and connect to original wire to that

only trouble is the original is in the theromostat so that wont work, so i was thinking would it work if i used the original sender and wiring and just connected the new guage to this? it has the same three wire and two for the bulb setup so should go strait on if this would work

also from looking at the wiring diagram iv noticed that there are two wires coming out of the speedo to a "Rev Limiter Bulb(if fitted)" does this mean that u could get these two wires and wire in shift light to work on the rev limiterby simply patching it onto these wires? seems odd that it comes from the speedo and not the tacho tho...

cheers

spike

[Neosophist]

Hey Spike.

Sounds like it can be made to fit.

The majority of temp senders work in the way that their resistance changes according to temp, if you look in the honda service manual it'll tell you the resistance values at specific temps of your original honda sensor.

Cross check this with data on the what the new sensor expects its values to be at specific temps, if they are close your new gauge won't be too far away if you wire it up with the original sender.

[Spike16]

hmm dont reall have any of that info to hand on the new one

I was thinking if i heat the bike to about 90 then swap guages if the new one also reads about 90 then were in business

[Gerbs]

Only bought my nc30 yesterday and am not too familiar with motorcycle wiring. i work in the manufacturing industry making chemicals and i routine temperature installations on a regular basis. Our temperature indicators (thermostats) work on a two or three wire set up. there is a resistance of 100 ohms across two wires and 0 ohms across the other two at zero degrees celcius. if your bike was two wires and reads about 108 ohms at 20 degrees celcius then it is this type of temperature probe (PT100). your new sensor should have three wires. measure the resistances across the wires. two of these wires will read 0 ohms when you measure across them. connect these two wires together and measure the resistance across the wire on its own and the two that are twisted together. if this reads about 108 ohms at 20 degrees celcius it should be compatible with your bike. the resistance across the thermostat should rise to about 134 ohms at 90 degrees celcius. hope this helps.

[Spike16]

the new sensor dosnt have any wire, ur ment to connect the original wiring to it

there are three wires going into the back of the temp guage tho and a further two for the light (same on the original)

im gona have a go matching temperature i thing, if it works then il fit the new one

[Neosophist]

That seems like a logical way of testing it.

Try it :D

[Spike16]

well it sems to work, it took too long to do the swap dials test but i heated th ebike up to about 70 (on the dial) stuck a thermometer in the rad cap hole and sure enough it read 70 so happy days + i reall like the look of it, very similar to the rev counter her's some pic's



why rooting around in the dials i found the block connector for the so called rev limiter light, does anyone know if this could be used as a shift light or not yet?

[royster81]

do you have any images of the connector block for the speed light ? or a description of where it was ?

[Leighio]

Another way and one which might of been a lot easyer prior to fitting would of to placed the sensor in hot water and check its resistance against what is given by honda and connected to the guage. This way if it did not work then it would not cause possible over heating of your engine and damge. Just a thought.

[Spike16]

no pictures of the block connector but i remember when i picked the bike up it was sticking out from between the speedo and tacho and when i found it this time its wires were leading back into the main loom (ie were the loom splits off into all the different instrument wire sets) it was a black plastic two connection block connector with the little tab to lock the wires together (identical to the one's that the rear brake lights go into

as for the method chosen i couldnt so that as its ment ot use the original wiring, so i basicly had the dial with three consctions and a snesor to screw into the rad, no wires in between, im gona heat the bike up through the temp range and check the dial is reading what the thermometer says before i get th ebike working atall, (just been comuting throug town were it never gets up to 90 anyway)