1990 dak 3.9 A500 auto longbed 2wd. factor cruise. utility bed. i have a nice long story. i have driven this truck 3 times so far. about 10 miles then 30 miles then back 30 miles. when i went to come home the other night the transmission kicked out of gear. like the trans was out of fluid. the engine also reved up when this happened. i was able to let the engine rev down and the truck kicked back into gear. but it wouldnt let me go over about 5 mph before it would kick out of gear again. i had only gone about a mile or two. i had a quart of atf+4 so i poured it in when i got to the stop sign. that filled it up. so i thought ok its good to go. it wasnt. it did the same thing. in all gears low 2nd and drive. so we limped the truck back to where we started from. at 5mph going in and out of gear all the way there. the next day i get back there to tow it to work on hte transmission . the truck starts up and drives fine. right up onto the car dolly. i tow it. when i get there the truck doesnt want to start too well. i had to crank on it a few times and then gun the enigne to make it run. i then drove it off the dolly. the truck seemed fine. so i let it warm up to see if the truck would mess up again. and it did. the fluid is very clean. not black not brown. so the clutches seem to be fine too. since it drives when the transmission is cool. other problems with the truck. the amp gauge is bottomed out. the oil pressure is pegged as far as it will go. water temp works fine. the fuel gauge likes to read correctly one time and then it will start reading backwards past empty. the cruise control no longer works. it worked on the first 10 mile trip. but not after. i have also not rehooked the a/c compressor lines. i also have one brake light possibly caused from a bad turn signal switch maybe. what i s wrong with the transmission? when putting it in neutral to check the fluid it gives a whining noise like a power steerign pump will make.

ok here is the back story on this truck. it hit a deer and i bought it from the previous owner. i had a 88 that i slide into ta ditch and bent the frame. my brother in law also had a 90 4wd with a bad trans. i took the core support off the 4wd and the engine bay harness. i uesd the bed from my 88 and front fenders. i also changed out the a/c box with the 4wd because this truck had a rat living in the heat box. and it stank. the map sensor plug on the engine had been chewed off by a rat. so the map sensor is not plugged in on this truck. since i have had it. i also swapped out the anitlock 7 1/4 rearend for my non antilock 8 1/4 rear same gear ratios. i had to also use my 88 driveshaft. because of the difference in lenght between the 7 1/4 and 8 1/4 housings. there isnt much difference but it is there. under the dash is a larger blue wire. it had ran out to the enige bay harness. but when i replaced the enigne bay harness i didnt ned it. but it was still rigged up under the dash to a white extension cord looking wire that comes from the fuse box and to the column and back to the inside frewall plug. it is obvious the wire had melted at one time. i have done no work or service to either the engine or transmission.

i know this i slong but i wanted to get the whole story down so maybe a correct diagnosis could be had. i do plan on hooking back up the map sensor plgu . that is the very first thing i am going to do. i am also considering replacing the interior wiring harness with the 4wd wiring harness. that may also clear up the instrument cluster issues. i hope i covered everything. i may have miossed one or two things. i hope not.

 

The large blue wire is a "Run". IT goes to the computer or a set relay. As far as the tranny, check your wires for faults/breaks near the transmission (driver side), since it has belly issues.

 

nothing wrong with the wiring. i checked i tout. i did find the kickdown lever unhooked from the transmission lever. i snapped it back on. that didnt help. could aworn front pump cause this issue? as soon as it cools down a few minutes i can drive it again until it gets warm enough to make it kick out of gear. i also put the map sensor plug on it today. that did nothing to help anything.