Hi Guys, Just received my 916 back from the garage after several weeks. One thing I have is the rev counter doesn't seem to be working. Speedo and temp fine. I have got the fairing coming off tonight - so could be a connection issue. However does anyone have any suggestions?
My rev counter was fine, then erratic, then wouldn't work when my battery was being fried by my reg/rec. Could be worth checking your battery is good and charging. Even if just to rule that out. (Monster S4 but similar setup I'd imagine).
If its electronic check where the plug goes in underneath. If its loose the socket inside the tacho mightve come unsoldered from pcb. Sealed unit but i have cut mine in half re soldered, glued case together and taped round it.
Brand new battery always on optimizer and new genuine ducati regulator rectifier just been fitted. revving away - needle stays at zero
My thoughts are - if i can get another working rev counter unit off ebay. would that be the highest chance of sorting the problem. Of that didnt work then im presuming thats electrical wiring etc?
One thought. If you have just had it back from the garage-presumably it was working when it went in? What do they have to say about it?
Ayrton, could be a few issues. The clock has a signal from the ecu, a 12v supply and an earth connection. The earth connection is shared with the clock lighting, the 12v supply is shared with the oil pressure warning light. The signal comes from the ecu via 3 multiway connectors. The earth passes through two connectors and power comes via fuse 6 in the fuse box. It could just be your reg failure cooked it. However there are a few things you can check, these are from a similar wiring diagram so the pin references in the main loom connectors under the seat and tank may be different. Pretty sure the wire colours have not changed 1. Check fuse 6 is seated and not broken, if you are missing the clock illumination and oil light this may be your problem 2. There is a trim screw in the clock accessible through the small hole on its underside, give that a little twist (but do not change its position) 3. Separate and check the ten way connector under the front rhs of the seat carefully check pin C or the grey/green wire path, reconnect. 3. Unclip the ecu connector, check pin 24 which is the ecu tacho signal out, reconnect. 4. Undo the round 23 pin bayonet connector under the front rhs of the fuel tank, check pins P (Grey/Green-signal) and pin T (black- earth), reconnect. 5. With the nose fairing off look for the 6 way connector for the tacho side, separate it, check pins 1 (signal), 4 (12v supply) and 6 earth. 6. From the tank side of that 6 way connector you can check the continuity of the earth at pin 6 to the battery - post, you can check that you have 12v at pin 4 (with the ignition on) and you can test the continuity of the circuit back to the ecu if you remove the ecu plug and bell it from pin 1 to the ecu plug pin 24. All that above will leave just checking the ecu output at the grey/green signal lead to the clock at the 6 way connector pin 1 - I can't remember the signal voltage (probably 5-12v) or waveform so best not faff with that and the ignition on for now. If all this fails you probably need a new clock. I don't think the clocks supplied for P8 ecus are directly compatible with the 1.6m bikes so be wary of buying
Thanks for the reply - sounding more complicated then first thought. Silly question - is it worth disconnecting the battery for doing all these bits - being Italian, I'm cautious of blowing ECU and electrics.
Ayrton, that's up to you. I would leave it connected so you can check the connections and energize the circuit as required. If you are worried about the ecu, disconnect the three way plug for the ecu/fuel pump under the seat (by the two fuses).
Ok - the rev counter is lighting up - so there is electric getting to the unit, it just doesnt not move when bike has revs. Would this mean more like a sensor problem?
As Denzil says in point 1, make sure the fuse is seated and connecting. I had an SS of this vintage and fuses connecting properly to the fuse holder was a definite problem. You need to make sure the fuse is flat and not twisted and slide the fuse in and out lots of times to remove any corrosion. Try the cheap, easy things first. Denzil made it number one for a reason
Hiya Denzil, do you know what each of these five connections do ? I am not sure which one does what. Thanks.
Crowned, the two wires are the signal + (red) and earth for the oil warning light and the rectangular plug contains the power supply for the rev counter (from the fuse box), an earth which goes back through the main loom and the signal wire which comes from the ecu.
Thank you ! Do you know if the tach would respond properly to a 5V signal, or does it have to be 12V ? I would like to make a signal to control it. Also, do you know the name / type of the rectangular 3-pin plug ? I saw that it says 4 C on it, and that the male is 4.5mm x 10mm, but I don't know where to find it. Thanks !
