I have a 2000 honda civic ex, the cluster was working sometimes but than it would stop randomly when i turned the car on another day. I changed my vss speed sensor and now when the cars on it goes to 20 and bounces when i drive. When the cars off it shoots up to like 70 than drops to 0 real quick, any ideas what this could be? I took a voltage meter and found that it is grounded but one wire near the sensor plug is ready like 14.5 which is battery power and i believe it shouldn't be ready that high.

 

check all your fuses. i had a similar problem on my old ek. the speedo would sometimes just go wherever it wanted. like id be crusing at lke 25 and it would spike to like 110 then chill out at 70.

i changed the vss twice, traced all the wires in the engine harness and the dash harness looking for a break and found nothing. then i realized i never checked the fuses and found the cruise control fuse was blown but was still close enough to arc and was sending f'ed up signals to the ecu

lesson learned that hard way: always check the fuses first...

 

have you recently replaced or played with any of you O2 sensors? if your O2 sensor grounds out against something it blows a fuse and messes with your speedo.. i know it sounds weird and i didnt believe it either till i experienced it first hand...