i have a 96 dodge 2500 with a real cranked up 12v. The tranny only has 1-3. No 4th or overdrive. It started back before winter where is would downshift from overdrive into 4th and catch overdrive again. My simple solution to get through was to throw it into overdrive with my lock-up switch so it would stay into overdrive. Over the winter I drove my 99 7.3 with a 6spd while I tried to figure out my problem with the dodge. I replaced my 4th and OD solenoid and governor solenoid. I cannot remember if I replaced the sensor with it though(it was back in December) and a new TPS. I took it out yesterday for the first time since December and i still have the same problem(didnt take it out because it has no rust and we have salt in NE Ohio. So here is my question....

What else can cause no 4th or OD?
What colors are the wires for the stock Tranny Temp Sensor so I can jump the harness with a 1k resistor?

Please suggest anything that makes sense that I havent already done.

Work done- built goerend 47re w/ suncoast triple disc, 250hp injectors, larger lift pump, 72mm single, 4k gsk, pump advanced 16*, no plate, lazer cut deliver valves, mighty diesel headbolts, custom ground haisly street cam, custom ground plugers and barrels in p7100

 

4th and od are the same gear. Are you saying you have 1 2 3 and no 4/od?

 

That is correct. 1-2-3...thats it

 

what are your readings from your TPS? you have no lockup unless you force it to lockup. 3rd lockup feels like another gear

 

If I try to manually lock it up by the switch it will not engage. This tranny is just going 1 2 and 3. No more

 

is the circuit open? bad solonoid? you mentioned you changed it already. that is a switched ground circuit, sometimes a build cold trans will not shift into lockup for several miles. mine takes prolly 5 miles if the temps are below freezing from a cold start.

 

Haven't tested that yet. I have been busy getting ready to easter at my house but come Monday I can get back to work on it. I just want some ideas to look for

 

Does it got to od and freewheel or slip or just stays in third and never tries to shift?

 

Yes is shifts first, second then third and doesnt shift again. This is a fully built tranny from goerend bros. hold up to 900hp. This truck is pushing 650hp-700hp(there was a another 12v with less done to it than mine with this turbo and made 673hp to the wheels. I know because I built it). Dyno to be done once tranny is fixed. This is electrical not mechanical problems. The truck has tons of power in the gears it has working right now. It will do more that throw you back in your seat, it will break the tires free when im cruising at 45mph in 3rd gear

 

sounds like a tps issue