1990 190e speedometer not working how do i attach cable

Speed sensor is probably faulty.

Here are some issues of Not working Speedometer*

1. The Drive cable is disconnected to a set of gears attached to the transmission,
**Common speedometer problems. **
-Faulty sensor
-Bad wiring
-Dial malfunctions.

I may suggest to replace speed sensor or drive cable

If it used the mechanical speed cable. Check the speedometer cable attachment at the speedometer in the instrument panel. Check the speedometer cable and speedometer sending unit assembly on the transmission.

You may of broke or disconnected the cable from the back of the speedometer to the transmission. Most of the time, it's the plastic gear on either end of the cable where it attaches to the transmission or speedometer that self destructs.

Check the transmission where the speedo cable goes into. It's located at the back of the trans. Removed the small cable retainer bolt and pull the cable out. See if the gear is broken. If it's not broken, have an assistant watch the speedometer in the truck and spin the gear at the end of the cable by hand as quick as you can and see if the assistant see if the speedo moves. If it doesn't move, replace the cable. It's most likely broken inside the housing or where it attaches to the back of the speedometer.

The speedometer drive and driven gears inside the transmission needs replacing

Removal & Installation The slightest bind in the speedometer cable can cause unpredictable behavior in the cruise control system. If the cruise control exhibits intermittent surging or loss of set speed symptoms, check the speedometer cable first

1. Follow the appropriate procedure given previously for removal of the instrument cluster. The cluster need not be fully removed, but only loosened to the point of being able to disconnect the speedometer cable.
   
2. Disconnect the speedometer cable and check that any retaining clamps or clips between the dash and the firewall are released.
   
3. Safely raise the vehicle and support it on jackstands.
   
4. Disconnect the cable fitting at the transmission or transaxle and lift the cable and case away from the transmission or transaxle.
   
5. Follow the cable back to the firewall, releasing any clips or retainers.
   
6. From inside the vehicle, work the speedometer cable through the grommet in the firewall into the engine compartment. It may be necessary to pop the grommet out of the firewall and transfer it to the new cable.
   
7. When reinstalling, track the new cable into position, remembering to attach the grommet to the firewall securely. Make absolutely certain that the cable is not kinked, or routed near hot or moving parts. All curves in the cable should be very gentle and not located near the ends. Note the speedometer cable inside the housing must be lubricated with the proper lubricant before installing it to the vehicle.
   
8. Attach any retaining clips, brackets or retainers, beginning from the middle of the cable and working towards each end.
   
9. Attach the cable to the transmission or transaxle. Remember that the cable has a formed, square end on it; this shaped end must fit into a matching hole in the transmission or transaxle mount. Don't try to force the cable collar (screw fitting) into place if the cable isn't seated properly.
   
10. Inside the vehicle, hold the other end of the cable with your fingers or a pair of tapered-nose pliers. Gently attempt to turn the cable; if it's properly seated at the other end, the cable will NOT turn more than about 1/4 turn. If the cable turns freely, the other end is not correctly seated.
    
11. Lower the vehicle to the ground.
    
12. Attach the speedometer cable to the instrument cluster, again paying close attention to the fit of the square-cut end into the square hole. Don't force the cable retainer.
    
13. Reinstall the instrument cluster following procedures outlined previously. Road test the vehicle for proper operation.
    

Your tach still works because it reads engine rpm. The computer uses info from the speedometer but the signals for the tach and speedometer come from different places.
I can't remember if your speedometer is cable driven or electric but the sender is on the drivers side rear of the transfer case output tailshaft housing. If cable driven check that the cable isn't broken inside (I usually put an electric drill on the cable and run the drill to see if the speedometer works (some run backwards) If the drill is able to make the speedometer work check the gear that is inside the transmission by removing the part the cable is attached to. That drives the cable. If electric, check wiring and if OK, replace the sending unit.

maybe speed sensor switch? usually located and attached to speedometer cable at transmission!??

Replace the Speedometer Cable

1 - Remove the old speedometer cable from your car, first take off the doghouse and then the engine cover.

2 - Remove the screw underneath the dashboard and take down the steering column. This will give you access to the back of your speedometer.

3 - Take off the drive shaft bolt, and "O" ring, insert the speedometer cable through the firewall.

4 - Remove speedometer cable securing clamps from the engine compartment and on the transmission.

5 - Release the drive shaft nut from the "right angle" adapter (The nut is attached to the back of the transfer case).



Installing the Speedometer Cable

1 - Place the square end of the speedometer cable into the adapter and secure the drive shaft nut.

2 - Pull the speedometer cable through the firewall to the rear of the speedometer.

3 - Secure the "O" ring and attach the speedometer cable to the rear of the speedometer/odometer. It should be engaged in the speedometer's square hold. Tighten the drive shaft nut again.

4 - Replace the clamps that will secure the speedometer cable onto the transmission and in the engine compartment. Replace the engine cover.

5 - Drive your car slowly to be sure your speedometer is working properly. If it is, replace the doghouse. If you're stilling having problems, take the car to your mechanic.


Parts & tools -
Speedometer cable
Wrench
Screwdrivers

Good Luck.