I've aquired a Ducati Peformance tachometer and housing unit for my 2000 M750. Everything is connected but I dont get any reading from the tach. The needle moves ever so slightly but I think its only from vibration. Is there a way I can determine if its defective or troubleshoot what the problem could be? If I was to hook up a voltmeter to the end of the harness what sort of numbers should I see?
anybody?
I forget exactly which wire you'd use to connect one of the older tachs.
On the FI models you tap into the signal wire for one of the coils (smaller connector, I believe)
Unfortunately I has no idea what the connections look like on the m750. If IZ_ memory serves me correctly, it's a gray wire going to the Vertical Coil.
its a fool proof wire harness that comes with the tach. There are a total of 3 wires (red/black/green). When I turn the key on any try with a test light I get good power and ground, so I'm assuming that the green wire is the signal wire? If I start the bike and hook up a meter to the green wire will I get reading of any sort?
yup its the grey wire coming from the vertical cyl coil (coil on right)
hmmmmmmm.......... I'll have to check to see if that gray wire connects to the green wire leading to the harness at the back of the tach. How can I test the gray wire to see if I'm getting some sort of signal? Do I just use a test light or do I need to hook up a meter and what should I see?
Quote from: COP TZR on July 19, 2010, 06:52:38 PM
hmmmmmmm.......... I'll have to check to see if that gray wire connects to the green wire leading to the harness at the back of the tach. How can I test the gray wire to see if I'm getting some sort of signal? Do I just use a test light or do I need to hook up a meter and what should I see?
I'd use a meter.
The signal voltage will most likely be the same voltage that triggers the ignition coil from the ignition pick up. I just don't know how many volts/millivolts it is.
could I jumper the power from the red lead to the back of the tach where the signal wire would attach to see if I get any movement of the needle? I really want to get this thing to work. If in fact its a faulty tach, can it be repaired? Is there anyone on the forum that does repairs like that?
I wouldn't put 12 volts to the signal input.
Quote from: ducpainter on July 20, 2010, 05:48:48 PM
I wouldn't put 12 volts to the signal input.
+1 on that, unless you really want a dead tach. Just take the housing apart - it's not hard! Give the little brass screws on the back of the tach a twist. I'd think if you have the tach hooked up & both cyls run, the signal is fine. The tach itself is sealed; I wouldn't take that apart.
Quote from: MongoReturns on July 21, 2010, 06:23:35 AM
+1 on that, unless you really want a dead tach. Just take the housing apart - it's not hard! Give the little brass screws on the back of the tach a twist. I'd think if you have the tach hooked up & both cyls run, the signal is fine. The tach itself is sealed; I wouldn't take that apart.
I've got the tach completely out of the cluster housing and see the 3 small brass screws. Should I remove them completely and re-install and tighten or just snug them up some more?
Quote from: COP TZR on July 22, 2010, 03:14:01 AM
I've got the tach completely out of the cluster housing and see the 3 small brass screws. Should I remove them completely and re-install and tighten or just snug them up some more?
Cool! Just snug them up, then plug the thing back in & turn bike on. Don't put the whole cluster back together yet! Fingers crossed.
Quote from: MongoReturns on July 22, 2010, 05:53:41 AM
Cool! Just snug them up, then plug the thing back in & turn bike on. Don't put the whole cluster back together yet! Fingers crossed.
I hope it works. Does it matter if the tach harness is plugged into the left or right ignition coil?
I don't think it matters, though mine's plugged into the left side.
Quote from: MongoReturns on July 22, 2010, 09:25:13 AM
I don't think it matters, though mine's plugged into the left side.
Mine is currently wired up to the right side, but I'll try the left side too if there's no success with the right side. Fingers crossed [bow_down]
Quote from: MongoReturns on July 22, 2010, 09:25:13 AM
I don't think it matters, though mine's plugged into the left side.
Thank the lord baby jesus and you very helpful people here on the forum. I did as suggested, snugged up the 3 brass screws plugged back into the right coil and still nothing. Then I wired it up to the left coil and it works!!!!!!!! Damn am I ever so happy. So if it wasnt working from the right coil, can that possibly mean I have a problem with it? The engine runs smooth and strong, so I dont think its defective. Its definately running on both cylinders.
thanks everyone.
Cool! I checked the M750 wiring schematic (it's folded at the back of the owner's manual) and the only difference between the right (vertical cyl I think) and left (horiz) appears to be an extra wire that runs to the yellow triangle on the original tach-less dash. Huh.
Anyway, I wouldn't worry about it - if one of the boxes didn't work, you'd not have a cylinder firing. Ride safe - it's a great bike. And put a dab of vaseline, grease or paint on those tiny little screws on the front of the dash - they rust!
Quote from: MongoReturns on July 25, 2010, 07:04:54 PM
Cool! I checked the M750 wiring schematic (it's folded at the back of the owner's manual) and the only difference between the right (vertical cyl I think) and left (horiz) appears to be an extra wire that runs to the yellow triangle on the original tach-less dash. Huh.
Anyway, I wouldn't worry about it - if one of the boxes didn't work, you'd not have a cylinder firing. Ride safe - it's a great bike. And put a dab of vaseline, grease or paint on those tiny little screws on the front of the dash - they rust!
thanks for the heads up!