...and I think you should hear a click from that solinoid when key on and switching the OD-off button. (when the engine is warm)

overdrive relay is a circuit board type control unit located near the ECU. It should also click, same as the solinoid. ( this is true of 1989. Trucks are different, so 1987 might be different)

also a switch in the shifter console.
also a coolant temperature sensor

not so bad.

should be 13 ohms on the solinoid coil. ...bettween the wire and the case.

On an 87, the OD temp switch (on the intake manifold, smallest single connector sensor - similar to temp gauge sender. to be sure, ground the sensor wire with the switch on. If it's the gauge sender, the gauge will go full hot when the wire is grounded. DON'T leave it grounded too long...) kills o/d when the engine gets too hot, not until it warms up. This was changed in later models for emissions purposes. I think it changed in 88 or 89.

The same temp sensor kills the a/c on an 87 in an engine overheat. It's the ground path for both the o'd and a/c relay coils.

Ok, I'll check for that also altho I think I tried that when you suggested it last time.If the A/C compressor is not on the vehicle yet do you think that would impact the ground path for the O/D relay? What do you think the temp sensor looking thing is on the pass side of the transmission that is housed in the top of the cooler line and has a hot wire coming into the top of it? I'm just not very educated on the KM series of auto transmissions and it is frusterating. My tranny experience is in GM and Ford 3 and 4 speed RWD autos.Guess I'll be more experienced by the time this is sorted out. Keep the ideas coming and I'll keep plugging away...... Thanks for all the help...

oil temperture warning light maybe.
does it light up when the key is on-engine off ?

so, was the OD solinoid functional?

Can I economy the fuel in the city when OD is turned off?

Turns out that I will not be able to troubleshoot until Sat or Sunday(7/14 or 7/15). At least I was able to find the wire coming down the drivers side that FASTEDDY was refering to. Thanks for the help.....

Temp sensor on pside oil line is tranny temp sensor for overheat light on dash, set to come on at 122*F per FSM.

The o/d relay grounds thru the temp sensor on intake/water neck, smallest sensor, single wire. Absence of a/c compressor will not affect ground path. Ground the sensor wire and see if you have o/d. Check sensor for corrosion preventing grounding. Or check with ohmeter for continuity from connector to ground...

TSB correction to 1987 sevice manaul p.21-104
When atf temperature rises above
cross out 50C (122F) and write 150C (302F)
the oiltemperature light comes on...