I bought a dodge 1500 and the speedometer doesn't work abs dings when I start the truck the parking brake light is on and the engine light is on for the vehicle speed sensor I changed the one on the driver side of the transmission but the light is still on and the everything is the same any ideas before I take it to a shop and have it fixed

 

There will be a speed sensor on top of your diff. Look pretty much right on top of the pumpkin and you'll see it. Replace that one and I bet all your problems will be solved.

 

Check the wiring and plug to that^^, if that seems good then replace that sensor.

 

I checked the wiring it looked fine and I changed the speed sensor and it did nothing I reset the computer after and still nothing

 

Should be another speed sensor on the LF hub

 

I'm surprised that didn't fix it. Sorry to waste your money, but it is an extremely common sensor to replace, that's why I suggested it. Pull the code before you throw anymore money at it. Your local parts store should pull it for free.

 

Pull the differential cover off and confirm the tone ring isn't screwed up or have bent, damaged teeth. Its a good idea to change the diff lube anyway. You only need 2 and a half quarts of 80-90w gear lube from wal mart and if you have a limited slip an 8 ounce thing of friction modifier. If you're on a super budget, save the lube & filter it and throw it back in, $6 permatex as a gasket is sufficient for the cover.

Theres a lot of fiction regarding speedo problems and our trucks. The speed sensor on the transmission is only used for gear selection and transmission purposes, it is NOT used to reference speed for the speedometer, nor is the front wheel speed sensor as not all rams have front ABS, there is a more common setup for this and that is the ABS controller on the inner fender wall via signal from the rear differential abs/speed sensor.

As others have said, inspect the wiring near the differential for damage, if it looks visually fine/untouched it probably is. Only as a last resort, revert to wasting time raping the wiring & testing continuity. Also check that your wiring for the trailer lights is not corroded or damaged as it shares a ground with the abs harness.


Normally step #2 is getting a new rear abs/speed sensor (on the top of the diff) and you've already done that.


Step #3: is to check the two harness connectors right behind the drivers side tire (next to mud flap) and disconnect & inspect them for corrosion, damage & possible debris and spray a anti corrosion electrical spray onto the contacts once you confirm they look good.


Step #4: if it still doesn't work, check for corrosion by the under hood fuse box and clean/replace as necessary.


Step #5: Check ABS controller connectors for damage/corrosion, located behind the battery and is the unit next to the inner fender wall.


Last step: Replace ABS controller behind the battery on the fender wall, as it is the last chain of custody before the signal gets to the speedometer cluster. It is the last step because it is the most expensive step in the speedo repair problem...average of $200 for a new/used one, sometimes you can find a deal for $100-$150.


The one percenter problem is that the speedo/gauge cluster is defective, but generally this isn't a problem on our trucks.


The red flashing brake light is for your parking brake, I honestly just disconnected my parking brake at the rear wheels as its never used and went wheels up on the brake release inside the truck, no more annoying light.