i just bought a 88 dakota its the se 3.9 v6 auto 3spd 140k when i got it it runs and drives,the po said the check engine light come on and off. well when i drive it i noticed it shifted kinda hard and the truck runs a little rough. the light came on and i did the key switch code read and got 2 codes first was code 15 speed sensor 2nd was code 33 a/c
well my truck never had a/c? and would the sensor be causing it to shift and run rough?

 

Shifting rough may be low or bad fluid or the TV cable/linkage.

As for the codes, try unplugging the battery to reset the computer and drive the truck again and see what comes back up.

How does it run rough? Suspension wise? Engine wise?

 

the idle is high then when driving and coming to a stop its real low, and it shifts into the gears fine but the speedometer does float like when driving. right now i have to put a radiator in it so i cant start it or check the trans level once i get that fixed ill check it or ill video what its doing.

 

ok i got the radiator put in but i noticed while doing that my - battery terminal was loose and im getting another code 12 battery input???? i took both terminals off cleaned them with wire brush tightened them and still that code is on? and my idle and that is fine it was prob the cold,the code 15 went off but when i took it up the road it came back on and shifted the same way,and speedo is doing the same, so could it be the speed sensor doing this? im downloading a video of it ill post later

 

The code 12 will always be there if the battery was disconnected in the last 50 times the key was cycled. Don't worry about that one. The loose battery cable would explain the funky idle. My truck would die on me at stop lights when my battery was spent. Effects the computer in some way. I would replace your speed sensor though. It's probably your problem. Good luck

 

yea seems to idle tons better after the fixed terminal and im going to try and get 2-3 used ones from the junk yard i know they might be the same shape but ill try first i can get one on ebay for $30 shiped so might do that if the yard ones dont work.

heres the video of it http://www.youtube.com/watch?v=p_vABHVrWzs

 

change the speed sensor. should fix the speedo and shifting problem, or at the very least, the shifting problem

 

Dang, that's the biggest fuel gauge I've ever seen lol

 

yea i know haha, another thing i need to find a wiring diagram of the inline fuseable links from the battery to harness,the po has some hack job done and i want to fix it back right.

 

There are downloadable service manuals in the FAQ that probably have that in it. I've also been surprised at the amount of wiring diagrams I've found just by googling.