What if Resistor Mod ?

Hate to be rude about this , trying
to keep replies , to the correct answer
and not confusing, to many that have done this mod

Since ECU is involved in tricking a sensor
as to which gear it's in .

To whom it may apply ,
All you electronic greek's out there .
That know the answer !
Not the one's , giving their opinions , and or
educated guesses .

The ECU is very expensive to replace ...
since it wired to ground now ( as in below link )
http://content.glidesociety.com/image.aspx?id=f8ccd98e-891e-40c7-bc22-abd7cfa78f41

What would happen if the resistor burnt up
and failed ?

Reason Asking !
The OEM connector wire that's cut
is @ the rear of engine and gets quite a bit
of heat back there .
Temp Range: -67°F to 158°F
680 ohm 1/2W 5% Carbon Film Resistor pk/5 - RadioShack.com

I'm hoping it goes back to original Triumph
advance first 3 gears

PS: If replies turn out good & not confusing
Maybe could be moved to RESISTOR MOD sticky

Wayne

I'm not a mechanic, but it's discussed here...

R3 Owners.com :: Log in

Ratboy ,

Thanks , but I've read all that .
I am a mechanic by trade ( retired ) old fart
but I'm Not up on all the electronic issues

The answer I'm looking for was not discussed ,
Resistor failure & what would happen

Regards
Wayne

Wayne - if the resistor fails, since it is wired in series, it would be like having an open connection. So I figure the fault light would go on and maybe the bike would running "limp home" mode?

Pig9r ,
Thanks , never thought of that one .
Makes sense , I worried it ( ECU) would short out .
Being open no connection .
4 spare resistors

Wayne

I know many many people who run the same resistor mod on their suzukis. I even ran one for a while on my Hayabusa (I didn't like it). I've never heard of one failing. Ever. Even if it does, I doubt it would cook the ECU.

I haven't done the resistor mod but it is probably set up like everything else...

The ECM supplies a 5 volt reference voltage down that wire. It is measured in milliamps. It is supposed to be grounded to a certain degree, and that is supplied by the resistors in the shifter switch. The resistor actually lets some of the current through to ground and the ECM "senses" that. The less resistance the more current is grounded and you have a voltage drop in that wire, in other words it would go to something less than 5 volts.

So... in this example the ECM is designed to be grounded through that wire. If you were to ground that wire completely it would not burn up the ECM... it doesn't care if that wire is grounded. What would happen is that the ECM would get an incorrect voltage reading in that wire and it would think that you are in a gear that you probably are not in. So your bike would not run at it's absolute best, but chances are you would notice very little difference.

I'm not even sure if that wire were to short to ground if it would throw a check engine light. The Triumph ECM may not be that sophisticated.

As the Piggr said, if the resistor burnt up you would more likely than not have an open circuit in that wire, not a short. So nothing would happen. But once again, the ECM may think your bike is in a different gear than it really is.

I think in the greater scheme of things this is a pretty safe mod to do. You could probably do more damage by hitting a squirrel or hooking up the jumper cables backwards