ok I know similar posts have been made but I think mine might be a little different. I have a 95 f150 5.8l automatic 2 wheel drive. my problem is the speedo stopped working and the trans shifts hard I have already replaced the speed sensor on the dif but it didn't fix it and also the overdrive light is not blinking nor is the abs light. some other info that might help is it would blow the fuse about every four months or so and the overdrive light did blink then and replacing the fuse would fix it until it blew again but now no fuses are blown anywhere. another problem I am having is my rear brakes used to slowly lock down when the emergency brake light and abs light would come on and I eventually melted the rear brakes hauling lumber when the lights came on and had to completely rebuild the rear brakes including the ebrake cables which where seized up and now the lights still come on from time to time but don't seem to lock up any more. and one time long ago my truck went into limp mode and so I opened up the cpu and found the board had blown about five capacitors so I soldered in new ones and its never done that again sooo….any ideas? my main concern right now is the speedometer and hard shifting.

 

Dont know if i can help but I can try lol. Sounds to me to be an electrical issue like wiring or bad ground. This is a pain to figure out. I would start with the fuses that have blown and trace all the wiring make sure you dont have any bad wires. do you happen to have an error codes?

 

If your dome light is out, check the fuse. The trans and dome light are on the same fuse

 

I have not checked that to be honest, but wouldn't the check engine light need to be on. but I guess the bulb could be blown sooo… I guess i'll check on that and get back to you. thanks for responding BTW.

 

??? I don't know, when I got the truck it didn't have blubs in it and I never bothered to put any in it. SOOO I guess I need to do that and see if it functions or not. i'll check on all this and get back to you. Thanks.

 

PSOM may have failed.

 

Silly, I know. My son (9yr old) has been up on the cab of my truck twice. While running RC trucks. Both times my speedo goes out with the dome light because fuse blows.Never have driven more than 3 miles in that condition.

 

Maybe pull the diff cover off the rear and check the condition of the speed counter ring behind the ring gear. Sounds like computwr isnt getting the speed sensor signal either to control transmission shifts. I didnt think the e4od or the aod-e would shift at all without knowing vehicle speed. Regardless, i would speculate the gauge may be ok but the wire from front to back or speed sensor or counter ring. Rust threw my speedo off at various speeds

 

The PSOM (as mentioned above) has a big, fat capacitor just like the leaky ones on the ECU & when the unit fails it will put the trans in limp.

I pick PSOMs up in the junk yard where others have destroyed the speedo & cluster surrounds.

I'd pull the hi-mount cab/3rd brake light & fix the melted sockets & check the gasket too.

Clean the original VSS & pull the one out you replaced.

Just suggestions.