I have a 1994 Honda Accord LX sedan and the speedometer just stopped working. My mechanic just put in a transmission that he bought from a junk yard. How do i fix this problem?

Blinking of the D light is a message for detected trouble in the transmission. The transmission needs badly the speed information for proper functioning. A faulty speed sensor / cable anywhere will cause the transmission to protect itself, and display a malfunction. If not mechanically inclined, take vehicle to shop and have them inspect the speed sensor / plug / wire that attaches to transmission bellhousing and the other connections associated with it.

Do an Internet search for speedometer repair shops. They rebuild them and they usually charge less than a junk yard unit

The speedo head or cluster is the part that houses the speedometer and tach, etc. now it may be the speedo cable that comes from the transmission to the speedo head that has broken. If so replace the cable and your back in business. If it is the head you can get them from your local recycle yard.

replace your speed sensor

If all the connection and power supplies to instrument cluster are ok,I suspect that the speedometer or instrument cluster is faulty but before you replace it, make sure the gear inside the transmission that drives the VSS is in good.

go to a junk yard, they are way cheaper and the chances of them going bad are very slim..

The cheapest place to start is to replace all of the vacuum lines. If they are old, dried out, and cracked, that might be your problem.

Has the speedometer failed to?? if so, you are probably in need of the cable that runs from your transmission to the back of the speedometer.This item is called the speedometer cable.If just the odometer itself failed then you have to pull the cluster and have it serviced typically i take mine to the dealer if that happens. (just the cluster,not the whole car.) hope this helps.

A green flashing "S" is similar to a check engine light. It is telling you that something in or on your transmission is not functioning correctly, such as the speed sensor or shift control solenoids. If it starts flashing and the speedometer stops working or the transmission shifts weird, take it to a mechanic.

Starter is not seated properly and is cocked sideways. Remove and reinstall, making sure it is fully seated