My check engine light came on, the transmission stopped shifting and my speedo didn`t work either. I replaced both speed sensors and it still doesn`t work, what else can I try. the car is a 2000 Dodge Intrepid

run the fault but all you describe is operated from the VSS sensor ( vehicle speed sensor)
it tells the cruise control the vehicle speed , tells the TCM the vehicle speed so that ratios can be changed, activates the speedo,and will report with a check engine light to report a transmission problem
run the fault codes first

Just a guess but maybe your vehicle speed sensor... does your speedo act weird?

You could try that first but it could also be a wiring problem.
Usually when the sensor fails your speedo stops working.

Assuming that your van is driving smoothly and your gears are shifting smoothly, start by checking your tranny fluid level. If it is low, that may be one of a few possible problems. If fluid level is fine, your speedo sensor may have a loose connection or could be going out which is what may be triggering the check engine light. I had that happen on my Jeep Cherokee. Speed sensor stopped working and the light was on constantly. Remember, if your speedometer sensor does not work, your odometer and trip meter will not turn either. Speedo sensors are not very expensive and pretty easy to change. Start with the easy tasks first: check fluids, check connections, replace sensor. If that doesn't work, get it into a shop (or talented and well tool-supplied buddy) and get a code(s) for the problems. Good luck!

The sensor should be in the side of the transmission.
The speedo would stop working, or you would have shifting troubles with the transmission. And you would have a check engine light on with a trouble code for the sensor.

FIX SPEEDO MAY NEED A SPEED SENSOR AND IT WILL NOT SHIFT IF IT DOES NOT SEE THE OUT PUT SPEED

You are right in thinking of the speed sensor. You should also have a check engine light on if the sensor has failed.
The sensor is mounted in the side of the transmission and takes the place of the speedo cable.

code p 0500 is for the vehicle speed sensor (VSS) which works the speedo as well as the ratio changes
code p0720 refers to the output shaft sensor --ECM or transmission control module (TCM)
the vss reports to the tcm which reads the road speed and gear ratio and shifts the appropriate solenoid

I would have the transmission shop check out the transmission.
The transmission may have a soleniod issue.

Hello,
sounds like the (VSS)vehicle speed sensor is bad causing the speedo not to work and the transmission is not shifting properly because the computer can not tell how fast the car is going,have your local mechanic fix it asap so toy do not do any engine or transmission problems.as far as the heater stopping,I dont thing they are related.I will get back to you on the blower have a good day DB