alternator dead

girlfriends bike wouldnt start yesterday.

no lights, no nothing, dead to the world.

she called out breakdown, and they told her that the alternator was dead. it was a blown diode inside it.

i take it this is the regulator rectifier ? the black thingy usually located at the rear of the bike ?

do these just die ? or is there usually a reason behind it ?

the bike has a datatool alarm fitted, and is usually left on an optimate when not in use. but surely if these were going to cause problems, they would have done so by now.

it also rained that day, the first time the bike got wet i believe.

she has taken it to a dealer to have a look at , any idea's how much this is gonna set her back, compared with buying the parts of ebay and fitting em myself

cheers boys (and girls)

The alternator converts the mechanical energy from the engine into AC. The R/R converts this AC current into DC current to run the electrical systems.

If the R/R has gone they're quite expensive for OEM replacements, but you can do a botch-job replacment using a donor from an older bike I think as long as it's a 5 wire one (try eBay)

Your battery is likely to be dead as well, so I'd get another one while you're at it.

[timwilky]

There are a number of posts on RRs on this forum, a lot of good advice from Mr Squid. Do a quick search

The SV RR is notorious for failing, indeed my own went. It is a simple check procedure using a multimeter. I followed recommendations and fitted one from a 2005 CBR6RR that I bought for £25 from a breaker. If fitting a better one from a H*nda you have to be prepaired to savage the old dead RR wiring connectors and substitute them for the the ones on the replacement which means 10 minutes with a soldering iron and a bit of heat shrink.

I would avoid buying a genuine suzuki R on Flea Bay as chances are it is already dead.

Originally Posted by sid of the spanners squid

First charge the battery and check the voltage across the battery terminals, (not immediately after disconnecting the charger, you'll get a falsely high reading), should be about 13V, much less and the battery is past it's best, do this first as some supposed charging system faults are duff batteries.

With the lights on and the engine spinning at 5000rpm there should be a reading of between 13.5 and 15V at the battery, if the reading is above 15V the regulator doesn't, if it's below 13.5V either the regulator is toasted or the alternator or wiring is goosed. This is a good rule of thumb test, but does assume that your meter is reasonably accurate, if you're not convinced your meter is accurate try this:
Ensure the battery is fully charged, start the engine, turn on the lights and rev the motor to about 5000rpm, what you're looking for is a rise in the reading of at least a volt, and when the engine speed falls back to tickover that it's still either equal to or preferably a bit above whatever reading you got from the battery alone.

Should the RR be declared "toast" using the above check, before you bin it, check the alternator output to the RR. Disconnect the 3 yellow wires to the RR and having turned your meter to AC measure the voltage between each wire with the engine running, you should expect to see somewhere around 75v accross each 3 pairs.


To test and replace if necassary an RR I guess you are looking at no more than 1/2 an hours labour.