Last year, after a work shop visit, the rear right turn signal was flashing fast. The front right was not. A back up turn signal wasn't either. Shop blamed the instruments. Their remedy; one (only one) wire was arranged from the rear to the front. I have had two fast flashing right signals since then.
Today I plugged in another working programmed instrument. Same result. ???
The multimeter shows voltage up and down on the good left side. It shows around 11 volts steady on the front right side harness derived wires - which strangely do nothing to a turn signal.
Incandescent or LED? If LED, what are you using for resistors?
Offhand, I think finding the voltage drop might fix your problem.
Thanks Howie,
incandescent bulbs. One/the weird thing here is that I find steady voltage in the two wires for the front right turn signal, but it's not resulting in any light.
If those two wires did NOT give any voltage reading, I assume the answer would be in the harness... I suppose it can be in the harness anyway... series of damages MAKING voltage at the turn signal, but confusing the instrument which triggers the fast flashing..
Should I measure the voltage coming out of the instrument?
Yes. Also make sure you have good continuity to each bulb from the dash and good grounds should be your next step. Include the switch in this check
Replaced the switch in the same operation [thumbsup]
"Good continuity"? That's when I switch the multi meter to ohms, right? What's a "good" number? How do I know I have "good grounds"?
Yes. Close to 0. Voltage drop is better. https://www.bing.com/videos/riverview/relatedvideo?q=voltage+drop+test&mid=0B76E6DFC7B0B6080A030B76E6DFC7B0B6080A03&FORM=VIRE
My very basic meter doesn't seem to have a voltage drop monitoring function.
To find out what "comes out" of the instrument, am I ok putting my red probe(?)/needle into the wire for the signal in question? Black needle in the common instrument ground or ground somewhere else? (if so, where?)
What's the usual voltage reading from a flashing signal (think the meter displayed roughly 3 - 10 volts), but what does a fast flashing voltage look like, on a basic meter?
Should be 12 volts. Min/Max makes life easy, but not necessary, just keep your eye on the meter. In my younger years, all we had were analogue meters.
I appreciate the help, Howie [thumbsup] However, there's more 8) If there is something broken/worn in the harness, perhaps creating shorts, will that disturb my attempt to read what's "coming out" of the meter? I plan to contact the wire connected to the signal in question, close to the instrument, and the other probe/needle elsewhere. Is this "elsewhere" the black wire coming out of the instrument or just any ground - like engine, frame and such?
If you have a short in the harness and the short is to ground you would be blowing a fuse. A short to another wire is possible. This would be tricky to pick up with a meter, too many variables. Eliminate everything else first.
My plan is to start close to instrument - on the positive wire. As asked, where do I connect the black probe/needle?
I'm close to clueless with electrical issues. So, be patient.
If the result is good (with my meter fluctuating from around 3 to 10 volts) there must be a problem elsewhere in the harness, right?
Then, I have a choice between looking for it in the harness (please no), replacing the harness OR arranging new wires. New wires sounds easiest...
Depending. If checking voltage drop on a connection or consumer, on the other side of the connection or consumer. Other wise, battery.
Yea, I agree, new wires. Partly because your bike looks really good after all these years. Give me some time to find a better voltage drop video and create a wiring diagram.
Ok [coffee] did some attempts today.... still with a basic multi meter.
From the instruments; right signal WHITE/GREEN, left signal WHITE/BLACK and one common ground black.
Tests done with three different bike instruments. Same results with all.
1 Left side voltage test by the instrument; normal flashing, from W/B to Bk, 0.5 - 9.5 volts. Testing on the turn signal end, same result.
2 Right side voltage test by the instrument; from W/G to Bk, 6-7 volts (maybe missing min max)
3 Right side voltage test by the rear fast flashing signal; also 6-7 volts
4 Right side voltage test on the harness front "end", where the front right signal connects; 11 volts, no light in the local signal.
5 Attempting continuity test; the meter set at 200K, from instrument W/G to frame 62.0, from instrument W/G to unconnected right signal (harness end) 69.0
Ideas?
Makes no sense to me. Those numbers mean nothing should be working. Give me some time.
At 200K, the meter display is 1_ _ and then the dot. Probes touching displays 0. The result was 62. and 69. Don't know if that helps.
My plan was to find harness trouble between instrument and failing turn signal.
The fast flashing rear is just a result of a malfunctioning same-side signal, no?
I've been busy all day, so I didn't get a chance to look at anything. Your readings tell me your blinkers should not be working at all. Yes,
QuoteThe fast flashing rear is just a result of a malfunctioning same-side signal, no?
would usually be correct. I have 0 knowledge what goes on inside the chip inside the instrument cluster. A PM to suzyj might help
Thanks for the PM.
There is some ungoodness happening. Your double-rate flashing is because the driver sees a blown bulb (= no or low current)on one of it's outputs. This may be a broken wire, which I foubt as then you'd see 0V on the front right indicator output, it might be a dodgy connector at the indicator or cluster, or it may be a damaged output FET on the driver chip in your cluster.
See https://ducatimonsterforum.org/index.php?topic=56614.msg1166122#msg1166122 for what's in your instrument cluster.
I think the next step is to open that up and have a look. They are very badly sealed so it's likely water has gotten in.
To stop the double rate flashing with a damaged chip you can disable the current monitoring, as I did to make it work with LEDs by cutting a couple of pins off the driver chip.
However this still isn't right, as the current from both bulbs is now being sourced from one FET in the chip, potentially stuffing it. If you swap to LED indicators this would be okay.
Thank You
I remember your instrument surgery very well. Curious, but never performed it myself.
One of the three tested instruments is new. The other two never showed signs of bad humidity damage. The results are the same on all three.
I find it very strange that all my "by/out of the instrument" tests show 6-7 volts on the front right wires. Shouldn't those measurements be unaffected? Or are they affected by harness issues?
What do you think about my strange continuity test? Harness issues?
My meter. Are the wires connected wrong, maybe?
(https://i.postimg.cc/8PHLK5x3/20250612-184906.jpg) (https://postimg.cc/ppm9y2WY)
Leads are correct.
I used to find something like this, the filament was broken in one of the bulbs and caused the relay to switch fast. a short to ground such as a broken filament falling down on another would do this especially if your harness goes back to a Body control module where it might have individual transistors instead of those old large ice cube relays.
Decided to leave the harness more or less alone. Double checked that I had continuity through the instrument plug before I and a friend cut the wire a few inches from the plug. New piece of wire down to the turn signal did it. "Keep it simple"? Works!
[Dolph]
Thanks for the support [thumbsup]
Yay!
[thumbsup]