I just purchased a 97 accord ex automatic. Once in a great while the speedometer will work and will so the odometer and the mileage meter but if the speedometer is not working, neither are the other two. Any ideas?

 

Does the CEL or D4 light blink or on(if not in D4)? Do these lamps work?(when turning the car to ON the warning lights should all come on, and then turn off when the engine is started). Check for any codes stored, under/behind the center of the glove box door, two wire blue connector. Jumper it with a wire, turn ignition to II(ON) and check for any codes from the CEL or D4 lights.

If no codes, it may be a connection problem either at the wire harness at the back of the cluster or the cluster/spedometer itself.

 

speedometer sensor is located on the back of the trans under the air intake. two 10mm bolts w/ extensions and wiggle it free. i would suggest buying a new one ($20) since a junkyard sensor will likely be broke also. this is very common.

 

It very well could be your speedo circuit board. The solder joint issue. Is it intermittent? When the speedo isn't working, does the needle stay around like 18-20 MPH? And does it suddenly start working again after driving for a little while?

The other issue could be your VSS, but if your cruise control is still working, then it's not your VSS.

I had this issue when I first bought my 94 EX. I removed my gauge cluster, took the back panel off, removed my speedometer circuit board and re-soldered each joint on the back very carefully and I have not had one single issue to this day. That was almost 2 years ago. The issue is because of old solder joints that crack and lose a connection on that joint after many years. Our year Accords displace a lot of heat behind the gauge cluster and so after driving a little while, the heat builds up behind the cluster and re-solders the cracked joints temporarily, hence the intermittent speedometer. When you turn the car off and let it cool down, the solder joints harden back up and crack again.

Hope this helps and if you need further details on the resoldering, don't hesitate to ask!

Good luck!