changing relays of cbr600rr

[mm davari]

hi guys.
I wanna know if any one who has work on wirig of rr or other similar engines had any problem since changing any of relays.
our problem is that once while we were working on engine it stalled at once.we reversed the position of them and engine worked again.but after a while again engine failed and changing the order didn't work any more.we changed the relays but every time after every one start, new set of relays would fail till the last time that no any relay couldn't be usefull.what do you think friends?!!

[mm davari]

hi guys.
I wanna know if any one who has work on wirig of rr or other similar engines had any problem since changing any of relays.
our problem is that once while we were working on engine it stalled at once.we reversed the position of them and engine worked again.but after a while again engine failed and changing the order didn't work any more.we changed the relays but every time after every one start, new set of relays would fail till the last time that no any relay couldn't be usefull.what do you think friends?!!

[PatClarke]

Hooly dooly MM Davari!!

You are doing exactly what I tell my students NOT to do. EVER!
These relays are invariably ground switched through a solid state device on the ECU board. They are ground switched because the voltage after the load (the relay coil) is virtually zero, so there is little heat generated in the switching.
These relays are invariable 'protected' with a resistor or diode across the coil. This is to prevent back EMF voltage zapping the earthing device.

So a non protected relay or a faulty relay can easily damage your electronics.

Never swap suspected faulty relays. They are cheap, so always keep a supply of known good (appropriate) relays and immediately throw outsuspect ones.

I hope you havent killed your ECU.

Regards
Pat

[Fabrik8]

I'm not sure exactly about the OEM relays used on the CBR, but there are many relays out there for OEM small engine and motorcycles that have a either a suppression resistor or diode built into the relay body. Usually they're built into the drive circuit, like Pat said, but never assume anything. You should be able to find datasheets on most common brands of relays and look up the relevant suffix or prefix in the part number to see if there is any extra suppression built in. I think the R6 relays have something like that built in, but I don't use the OEM relays (or harness) and I don't remember.

So what is failing on these relays, are the coils going bad? Killing relays is a little more serious than killing the drive circuitry that swithches the coils. I'd almost believe there was a bigger problem here than just the relays..