As far as the transmission, no suggestions, sorry .
As far as the radio, check to make sure power is getting to it, the back of the radio will have two connectors, a red and gray connector. We only care about the gray one. With the key off, there should be battery voltage at only cavity 7. With the key in Accesory or Run position, there should also be battery voltage at pin 6.

[IMG]local://upfiles/948/05EA63DE242049A4A1D8A120E4789F45.gif[/IMG]

 

Third update: Replaced the vehicle speed sensor, still no OD. Replaced the OD switch in the dash, OD worked twice, but then quit working today. Each time it worked it took about 15 minutes of driving before it worked. Don't think the switch is bad. Replaced engine coolant temp. sensor (located right beside thermostat housing on left if looking at engine with hood open) still no OD. I pulled some codes tonight from the PCM. 12, 45, 37, 55. Can anybody tell me what these codes mean. I have still not gotten a service manual yet, but I found one for a 95 and I need to send the guy a check, but little short on cash right now after changing these parts. With these trucks having so many problems with the OD, I can't believe someone doesn't have a fix. Thanks for the help. PS: the radio started working again........

 

Codes:
12 Battery disconnected within last 50 key-on cycles
37 Trans temp sensor no temp rise after start, or trans temp sensor voltage too low or too high,or torque convertor clutch no RPM drop at lockup, or torque convertor clutch solenoid circuit, or park/neutral swtich stuck in park or in gear
45 governor pressure solenoid control circuit, or trans 3-4 solenoid circuit, or governor pressure not equal to target @ 15-20PSI, or governor pressor sensor volts too high or too low, or trans 12 volt supply relay control circuit, or 3-4 shift solenoid no RPM drop @ 3-4 shift, or governor pressure above 3PSI in gear w/ 0MPH, or governor pressor sensor offest volts too high or low, or o/d swith pressed (LO) more than 5 minutes
55 End of Codes

12 and 55 are nothing to worry about.

It only had one wire coming from it (probably purple)? If so, thats the one that feeds (only) the temperature gauge. There is one on the other side of the radiator hose, with a 2-wire connector, that tells the PCM the engine temp (don't ask me why they did it that way).

Unfortunatly, my wiring diagrams evidently do not perfectly fit your truck year. If ya want, I can go ahead and post them up (I believe the wire colors are the same, but the PCM connector I believe is differant, mine has 3 differant connectors).
However, I am currently bidding on a 1990 and 1992 service manual for the Dakotas. The reasoning for the '90 and '92 is 1.) the cost is right [about $10 each, plus less than $5 shipping], and 2.) the years are the best variety [from 1988-1991 the V-6 and V-8 were throttle body FI, and from 1992 on its the good old multi-point FI, so thus the wiring varies a little], as it appears my '96 is a little too "new" for pre-96 trucks (such as the PCM on mine has 3-32pin connectors, while evidently previous years had like 1-60pin connector.) See, I do care about ya'll .

 

I coolant sensor I replaced had 2 wires, the one for the computer. The single wire one goes to the guage in the dash. That one works. There is a sensor in the intake manifold on the right side, front. Not sure what that one is. Going to the solenoid connector on the transmission, there is a orange/green wire, a blue wire, and a orange/black wire. From what I have found out so far, the blue wire has 12v when the ignition is on (which I have tested and is working). The computer completes the ground to activate either the OD solenoid or the torque convertor lockup solenoid. The lockup solenoid works perfectly. It will activate (unlock) when you step on the brake or push in the OD switch in the dash. I'm still trying to figure out what conditions have to be met in order for the computer to activate (complete the ground) for the OD solenoid. I may try to jump the wire to ground to see what happens. Dodgerules, does your wiring diagram show a orange/green, blue, orange/black wire going to the OD circuit? Thanks for your help.

 

The sensor on the intake manifold, its close to the throttle body, thats the intake air temperature sensor.

Out of the wires you asked for, my wiring diagram shows the following (and what they are for):
(light) Blue - 12 volt supply from transmission relay
orange/black - torque convertor clutch solenoid control

Do you remember how many wires were on the connector for the transmission, because my service manual is showing it as a 8-wire connector.

 

Mine is a 3 wire connector. Later years had the larger connector because there is a 3rd solenoid in the transmission. Thanks

 

Fourth update: Well, today I wired a switch to the OD solenoid to make the ground as the PCM would. I had power to the Solenoid and the wire from the PCM to the solenoid is good. Test drove the truck, reached operating temp and was running about 50 mph. Threw the switch, nothing, no OD. The solenoid is receiving power and activating, so my problem has to be in the transmission. I've got a 93 service manual, followed all the test procedures. The only thing I don't have is a pressure gauge to check the transmisson hyd. pressure at various ports. May be time to take it to a transmission shop. I may try a transmission flush service. I just can't figure out why sometimes it works and sometimes it doesn't. Very frustrating. I'll let you all know what happens.

 

I just posted (gutzy) with sort of a similiar problem, however, my truck is a 1991 Dak 3.9L 4x4, Automatic. Could our truck problems be compatable, given the different years etc?

 

I have a 1993 dakota just like yours, i rebuilt it a few years ago. There is large black wire connection block on the passenger side. When i put my truck back together i didn't have this together tigh enough.Had the same problem with the overdrive not working.
Hope this helps.


Mopar400

 

im having the EXACT same problem. i havnt looked at mine yet. i havea feeling it has to do with moisture. i went muddin one day and the OD was screwing with me. once it " dried" out it worked fine.

the second time it stopped working just last week ( 3 months after the first time) i was following a truck in the rain. my truck was getting soaked!

and it happend again. its been raining the past few days here and its been acting horribly. i didnt really read your post, so i have nothing to add at this moment about what you said.. ha


Chad