AJH Posted September 26, 2021 Share Posted September 26, 2021 Hi, I have just brought a 1994 VFR 750 with what I thought was an easy fix speedometer fault, the issue is it not a mechanical driven unit but electrical. It could be as easy as changing the sensor. With the ignition on I removed the sensor and used a drill to spin the drive, nothing I would have expected something. Any tips before I purchase a Ben sensor? Link to comment Share on other sites More sharing options...
Member Contributer Grum Posted September 26, 2021 Member Contributer Share Posted September 26, 2021 Do you have a circuit diagram? Assume you have no other instrument panel issues other than your speedo? So no need the check Fuse A 10amp right? When spinning the sensor, Do you notice the odometer working or not? If it is working then that could mean the speedo movement is faulty. If both speedo and odometer are not working then carry out checks below. Before replacing the sensor! Make sure - - You have 12v on the Black Wire of the sensor ignition on. - You have solid Ground back to the Battery negative terminal on the Green wire. - You have continuity of the Pink wire from the sensor up to and internally of the instrument panel to the speedo mounting terminal sctew of the PCB (printed circuit board). The power and ground terminal screws for the speedo within the instrument panel should also be verifed. The instrument panel PCB can suffer badly from broken/open circuit copper tracks as well as poor screw contact to the PCB for the 3ea speedo connections. Other than that, you could have a stuffed meter or a speed sensor issue. You can download the Service Manual from this forum and pages 18-3 and 18-4 explain speedo and speed sensor testing. Link to comment Share on other sites More sharing options...
Member Contributer JZH Posted September 28, 2021 Member Contributer Share Posted September 28, 2021 And if you buy a replacement sensor, make sure it's not from a KM bike... Ciao, JZH Link to comment Share on other sites More sharing options...
Member Contributer Grum Posted September 30, 2021 Member Contributer Share Posted September 30, 2021 On 9/29/2021 at 4:54 AM, JZH said: And if you buy a replacement sensor, make sure it's not from a KM bike... Ciao, JZH Yep good point. 4 printed on the sensor = MPH, a 3 = KPH. Link to comment Share on other sites More sharing options...
Member Contributer airwalk Posted October 17, 2021 Member Contributer Share Posted October 17, 2021 Late response but maybe pertinent. Have looked pretty far&wide(e-bay, etc.), these are becoming scarce, as in NLA new. Just struggled thru a testing, grasping straws session with one of mine, turned out that sensor works but screws on back of speedo weren’t making good enough elec. contact with printed circuit. What a PIA, getting to back of instruments is beyond tedious! Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.