ok, on my 96 civc the speedometer doesnt always work, if i un-clip the switch on the tranny speed sensor and clip it back on it works for 1 mile then starts to hop and turns off ??



what are the possibole reasons for this ?

 

I had a similar experience when I installed an aftermarket cruise control in my Civic VX just weeks before my first cross-country trip. I clipped onto the speed sensor line but the cruise wouldn't engage. Then I noticed the speedometer stopped working. I eventually used the magnetic sensor with the cruise (and later the tach sensor because the shop that replaced the axles left it on the old half-axle).

Anyway, getting to the point, the speedometer worked for a little bit then stopped completely. I also got a check engine light. A trip to the shop and $400 later and I had a new speed sensor. Apparently they eventually die -- mine made it to 110,000 miles or so. I gather it isn't all that difficult to replace but I didn't happen to have the right tools to get it out (I assumed all I'd need would be a deep-well socket of the right size, but if I remember right, it was locked in there tight and the last thing I needed was to strip threads or break the sensor in half.)

I'd start there: diagnosing the speed sensor.