I took project beastie for its MOT re test today and success! Unfortunately I had to be rescued by the AA on the way home This bike is fighting me all the way! The bike cut out and refused to start. AA chap said the battery was drained, however the battery warning light didn't illuminate. Could this be the infamous Ducati rectifier? The AA chap suggested the battery may simply be done for, but why no warning light? How can I test the rectifier? I've checked the wires and no sign of frying. Thanks in advance.
First of all, are you running a 'conventional' lead acid battery? It could just want topping up after a long period on an optimate or similar. Its one of the things I always look for when bringing any of my bikes out of hibernation. Secondly, the way to check for charging is to get a multimeter and put it across the battery when the bike is running, at tickover it should be reading about 13v or so, next rev the bike a little, and see what happens, the reading should go up to about 14.5 or so, max. Any more indicates that the reg rec is goosed, this will also produce the symptioms in the first paragraph, as well as blowing bulbs etc etc. Also pull the connector from the alternator (with the engine shut down this time) and see if theres any sign of distress on the connector plugs, Ducatis are famous for melting the insulation around the connector plugs, although mine has always been fine, and as far as I know, the reg rec is the original and 20 years old.
When I got home the battery was down to 6V, wouldn't even light the dash! I've got it on charge now. I'll try those tests. Birdie, yes it's the 748 loom and dash. What's the battery light on the dash for?
Birdie is spot on re the light. My 916 BP had charging light, but both my 916SPS and 998R have the same warning light cluster but no bulb, guess Ducati figured if the light came on you may worry about your rectifier/charging so best thing was not to have a warning light ! Got to love Italian logic.
The early 748- 916 had a charge light but a crap regulator, Ducati upgraded the reg but forgot the charge light on later models. Steve
My 748 is 1998 no charge light, as I said the reg was replaced very early on. However I have fitted one to my bike now. Steve
So it's not as simple as old reg = charging light. New reg = no charging light. Well, it certainly sounds like mines missing...
I think , when the reg was upgraded the wiring was changed as well. If anyone knows different I'm happy to be corrected. Steve
Have you checked the alternator to regulator (yellow wires) block connector behind the battery holder for corrosion?
Not knowing much about electrics so don't want to confuse you in any way, you have 748 wiring which was for a two phase alternator but you have fitted an engine with a three phase alternator, could there be a problem there. something to consider.
Had quick look at the wires, going to have a closer look tomorrow. They were ok when I fitted few weeks a go.
I don't think it will make a difference as I fitted the 3 phase rec... Happy to be corrected as I'm no electrics expert. :frown:
It was the very early ones that had the charge light.The thing that really kills reg/recs is heat.They need to get rid of heat readily.Got thru quite a few on a blade I had.In the end I fitted a fan that came on with the ignition,that seemed to sort it.
