Does anyone know if there is a specific earth point for the headlights or the instruments? Hunting some issues and it would make sense if there was at least one of the above. Cheers, A
According to the wiring diagram it is a black wire that joins all the other black wires on the bike. The whole frame is earthed and I know from experience that the headlight mounting is a good earth. Does that help? If you are having suspected earth problems then an additional wire spliced into the black from the headlight and earthed to any frame fitted mounting bolt in the area should help diagnose your problems.
That is fair enough but it should not be a poor earth. Obviously these bikes are not spring chickens any more and corrosion and crud can change things over the years. When I bought the ST2 I went over the whole bike with the fairings off and a ohm meter connected to the battery earth and checked the resistance to most parts of the bike. I was lucky on the ST2 as there were no problems. The BMW K100RS that I restored needed quite a few bolts removing, cleaning up and then refitting to make sure that everything was well earthed.
OK, took an earth for each headlight earth wire to the headlamp mount either side. Have not had a chance yet to see if it has made a major difference as I need to get it out and up to temp to see if the issues are apparent.
Got the bike out for a spin today and there is a definite improvement. When pootling along below about 4k rpm, there is a slight waver to the tacjo needle as the various electrical loads come on, but nothing notceable above that. More to the point, the jump in the temperature reading was drantically recduced. Now, when cruising about 5k rpm, the temp indicator jumps one degree when the dipped beam comes on and another one when the high beam comes on. That is a lot better. Plus, cruising at 120kph, no amount of high beam flashing by the pass button or the high beam switch could prompt it to drop one one cylinder. I'll reserve judgement for now, but that sounds like a win to me.
Another thing worth checking is the multi connector on the lhs of the fairing. The connectors usually stay clean, but water can sit in the lower shroud, corrode the cables and backs of the connectors. Pull it off and check. Clean and grease before reassembly.
The change in reading for the dash temp display could also be voltage drop due to a weak regulator/rectifier, or the power supply to the lights. Mine did this before I added some extra relays for the headlights. I changed the Reg/Rec to a MOSFET one from a CBR. Wierdly, connecting all the earths together made it worse, so I added a separate earth for the lights back to the frame/battery and this helped it. The connector on the LHS of the frame was checked and found to be in very good condition, the PO of my bike obviously kept an eye on it. The spring chickens comment made by @Bob T above is a good one, and some of the loom could be becoming high-resistance.
Right, did not think of the reg/rec. Having had Hondas before I'm all too familair with issues, but they generally just die as oppose to expire over a period Do you have a bit more detail on the CBR reg/rec to replace the OEM one? Cheers, A
Sure, I think it was one from a later (2008?) CBR600, but most are similar. I believe Yamaha R1 parts are common for swapping onto all sorts of bikes too. Earlier regulator recitifiers (like most older Hondas and the ones fitted to the 3-wire alternator Ducatis are "Shunt" type - i.e. they dump excess electrical energy to heat. The MOSFET ones don't do this - they regulate in a different way, so run cooler and apparently don't die quite as often. About the best how-to guide I've seen on t'Internet is this one :- Charging System Diagnostics - Rectifier/Regulator Upgrade - Triumph Forum: Triumph Rat Motorcycle Forums I have no affiliation with this site or the author, but it seems like a pretty comprehensive guide. The wiring to the original R/R needed modification to suit the new unit (lengthening and new connectors), and I added a direct link to the battery positive and negative terminals, with external waterproof fuse holder on the positive line. I used Super Seal connectors as the originals are open to the elements. I've put the new R/R in the same location as the old one (it's a snug fit and only uses one of the bolts, but it's been fine so far. Hope that's of some help.
Because I don't trust the electrics on my ST I fitted a small voltmeter. You cand see it here on the left of the dash. Electrical toys – Ducati ST, 2nd picture down. It has shown me a problem once when the regulator connector was getting hot and causing me voltage problems. These little voltmeters cost a couple of quid from ebay and are very east to wire into an ignition live from the fuse box. At least you will know when riding that if it is showing anything over 13 volts then it is charging. If you want me to search out the ebay link then let me know. I have one the same fitted to my BMW K100RS, it does give peace of mind.
