warden

Input please..
1996 2500 4x4. 146k miles, tranny fluid and filter power flushed by dodge dealer 20k miles ago. Stock in all respects.

About a year ago I posted about tranny going in and out of od. With everyone's input and searching previous posts, I cleaned the tps and it worked fine for about 11 months. In December, after a daily 160 mile round trip to work I noticed fluid leaking under the front end, tranny fluid all over everything. I started the truck up and discovered that one of the tranny oil cooler lines, next to the engine block, had a pin hole leak. I don't know how much fluid I lost or how many miles were driven with low fluid, there were no warning lights. Checked these forums again, called the dodge dealer and ordered two new lines. I assumed they would be the new type, but were the old style. I replaced the bad line and carefully added new dexron 3 to bring it up to the full mark, hot with tranny in neutral as per directions. I cleaned the undercarriage up, no more leaks and away I went. During the trip home that I lost the oil the trucked jumped out of overdrive several times, I turned the key off then on and it would kick back into od. Not sure if this was caused by low fluid or fluid shorting out a sensor or connection underneath. Tranny fluid now up to normal, but the truck kept going in and out of overdrive. I thought tps, I got a new tps from napa, $159., the dodge dealer quoted me $300+. Again cleaned everything up, installed the tps and away I went. Problem persisted, dropping out of overdrive, turning the key off and on would bring it back sometimes. I spent too many trips on the pike with 4 way flashers on doing 50-55mph to work and back. More research here, I started to remove the tps wire from the harness about 4 times, finally yesterday I replaced the wiring from the tps to the ?computer? (PCM) with shielded wire. I confirmed by color code and continuity, purple with white trace and orange with purple trace, made solder connections. I even put in a brand new transmission control relay in the relay box. In the process I disconnected a couple of connectors at the center, high fire wall and the pcm connector that had the tps wires. I the tested the tps for voltage as per the direction here on the board, measured throttle linkage (5").

Idle voltage was .956 and wot was 3.57. I removed the two metal sleeves from the tps and adjusted for a final of 1.102 idle and 3.67 wot...that's all I could get. I double checked all of the connections and went for a test drive----just knowing that it was going to be beeeautiful. Well guess what?

1. No tach, 2. I couldn't get my overdrive lockout light to go on, even after I turned the ignition switch on and off, and I could not get the tranny to shift up or down by turning the key on or off. Previously if it was in third and I turned the key on and back on it would sort of go into a neutral and then back into third. One other thing I did after putting it back together was to take crc contact cleaner and spray the transmission electrical connections. They still had oil and grease on them that I didn't get off before. Now to my questions.

What connector does the tach get it's input from? Is it possible that the tranny or torque converter is low on fluid even though it shows normal when hot on the dipstick? What is the exact location of the speed sensor connection on the tranny and what are the other electrical connections on the tranny? Did spraying the tranny electrical connection cause these problems? Thanks in advance any and all input is greatly appreciated.

warden

MnTom

Your tach gets its signal from the crankshaft postion sensor on the front of the engine by the harmonic balancer. The speed sensor is located on the top of the rear differential. I would think that the place(s) to start checking would be in the area(s) that you did the rewiring. There may be a plug that did not get put all the way back together. There also might be a plug that you didn't see that might have come unplugged. Double check all the wiring and let us know how you make out with it.
Tom

warden

Thanks to MnTom I got my truck and tranny fixed. The location of the tach sensor gave me the clue I needed Tom. I'll post the details on 12v engine and drivetrain.
warden