Fixing a Tacho

[Deicide]

Hi Guys,
Ive been trying to find the problem with the Tacho on the Across (1991 Suzuki GSX250F). Ive pulled apart the instrument cluster and had a look at the internals, everything seems fine. Im struggling to find where the problem is. Im assuming the "Signal Generator Wire" sends the signal for RPM to the Tacho?. Ive had the cover off and and all the connections look ok. Is it now a case of chasing wires to look for a broken one? Im assuming you set your Multimeter to Resistance and look for a reading between the wire to indicate a good connection?

Any help/advice would be great
Cheers

[Sentry]

Firstly, read the manual. If you don't know what signal type you're looking for you're not going to be able to determine the problem. Also, if you're pulling apart the cluster and you don't know what you're looking at/for you're more likely to do more damage.

To the obligatory reply "I don't have a manual", you should really have one if you're ripping things apart. They even show you how to check if something is working. I'll dig out a link if I can find a manual, but you may have to purchase one online.

What tools do you have? Do you have a multimeter/ammeter? Oscillarscope? (can I buy your Oscillarscope? )

[Sentry]

Ok, try http://www.carlsalter.com/aaman/Suzu...ice_manual.pdf
If that doesn't work, try Free PDF motorcycle manuals for download! and check under Suzuki GSX 250F. It contains from years 92-94, but I doubt there'll be many differences between your 91 and this manual.

[Deicide]

Ive already got the manual cheers Sentry, Have a basic Multimeter. Any way to easily check the operation of the Tacho ie, drop a low voltage across one of the connections?

[Sentry]

I'd have to look into your models tacho, but I'd suspect its a typical "5vdc pulse". You'd need a frequency generator to determine if its working and calibrated. I'd start with the simple stuff like your cable (by checking the cables resistance) and pick-ups. Not sure how your bike picks up the signal but if you check your manual it should tell you. More than likely, a connection has shaken loose somewhere so check all the cable terminals for the tacho system.

[browncow]

Make sure you wind the clock back before you put it all back together...

[spikes]

I had the problem with the tacho where it would underread the revs by about 2000 - 4000RPM, i gave up with it and gave it to the auto electricians, $130 later, they found my problem of corroded leads and put new ones in and fixed up all the connections.

Just an idea of where to start looking.
Good luck with it

[Deicide]

I pretty much gave up, tried tracing a few wires. Im guessing the Tacho itself is munted as it appeared to be getting a signal but not showing anything. Its the Mrs Learner bike so if she gets right into riding I'll think about getting it fixed.

Cheers for all the advice though