speedometer bouncing

[96obs7.3]

hey ive got a few problems on my 96 f350 after 40 mph the speedo bounces like crazy put in a new speed sensor and it made it worse, next problem is my horn and cruse controle will not work please help

[JSchuricht]

The speedometer could be several things. The most common culprit is the VSS. Should be about $30 at the dealer, sits on top of the rear pumpkin and is held on with one bolt.

For the horn and cruse to be out, I would pull the wheel and check the brushes. IIRC there are three or four spring loaded contacts stationary on the bottom right of the column that contact a series of rings on the wheel. Check to see if they are worn, broken or just dirty.

[JSchuricht]

Overlooked that you had changed the VSS. Try changing out the PSOM it's almost as common as the VSS. If you can get a cluster from a 92-98 truck you can disassemble it and swap the speedometer/odometer with your cluster.

[dcaddy]

I had the same prob with my speedo along with my tranny wouldnt shift into od. It was just a open circut in the wiring on my95. Follow the 2 wires leading from the sensor on the rearend and follow them up the frame. they should be tucked into the conduit but someone had mine pulled out and it was shorting out on the frame.