So i just picked up at 96 jeep. The speedo does not seem to work. Only the speed portion. The Odometer, lights, fuel all work but the speedo is suck at 15mph... Do i need a speed cable or replace the whole speedo. Is there a speedo upgrade that will allow me to have RPM? The driver seat is all jacked up and is now rocking. I researched it and im going to buy bolt and washers tomorrow to fix it on the cheap. The rear door seems to make a racket, i though it was because of the rear weather stripping is missing but that does not see to be the case. I might have to adjust the rubber stoppers to lessen the gap. Any input would be greatly appreciated.

 

First thing to check is the connectors (it's an electronic speedo and not a manual one with a cable) on the back of your instrument panel. One thing to do is while you're driving it to wack the top of the dash. Sometimes this works (if a loose or dirty connection) and sometimes it won't. If your other gauges work, most likely it's not just a fuse.
Next is to check the connector on the speed sensor (located on the drivers rear of the transfer case. If cleaning that doesn't work, there might be a short in the wiring between the instrument cluster and the sensor. Lastly, you may need to replace your speed sensor.
I kinda did this backwards because on my last XJ, the speed sensor was bad, so when it happened on my current one, I replaced it first when all I ended up having to do was to wack the dash to get mine to work.