My 89 Gen 1 Montero has sit idle (started up occasionally) for a couple years. Recently I started driving it again. It will not engage the overdrive (OD) clutch. The OD was working fine before it was parked.

I removed the OD solenoid and applied 12v current and I get a definite click from the solenoid. From my research this indicates that the solenoid is functional.

What other adjustments or electrical issues could be causing the truck to fail engaging the OD?

Thanks for your input !

Sounds like you need to get on mitsubishilinks.com and see the troubleshooting procedures in the FSM. Before you start throwing expensive parts at it.

I already have the FSM and I've looked at it thoroughly. Not all that helpful always.

I suspect it is something simple like a temperature sensor sending bogus data to the ECM. I had a mechanic from 2carpros.com tell me it likely has an OD solenoid relay somewhere. 2 CARPROS response provided an answered with a picture of where the OD solenoid relay should live, but, I don't find a relay in that spot. The FSM shows an OD relay in the wiring diagram, but that doesn't help with the location of the relay.

So, I'm not a junior at this stuff. I go to the manuals that I already have and of course YouTube and other sourses looking for answers to questions. YouTube is wonderful for some repairs.

If someone could help with the location of the OD relay, I would sure be pleased.

Thanks for your support.

Do you have the parts manual? It's on mitsubishilinks.

On PDF page number 312 (manual page 21A-92) there is a diagram of the automatic transmission. It looks like illustration part number 7 (valve assembly, solenoid) is the part you are looking for. The diagram isn't great, but it may help you get an idea of what to look for.

MarkG,

The solenoid on the Montero responds to the application of 12v current. Responds with a nice "Click". I don't know for sure that means it is "good", but I think it does. The FSM wiring diagram shows a "relay" in the circuit. The relay takes input from the ECM to activate the solenoid I would think. So I'm trying to find the relay.

FSM page 8-42 and 8-43 shows the relay (they call it a switch) as part C-33.(OD-OFF Switch). I'd like to pull that switch and determine if it is working. Since what we are looking at is a mere diagram and not a picture, I've been looking for the typical relay form factor. Maybe it is different than that.

I'm going to study the wiring diagrams and see if I can determine the wire stripes and colors and run it down that way.

well, I'm stumped. After going over the wiring diagrams, I should be looking for a 5 wire input connector to a relay/switch (relay like I assume) with a specific wire color as follows LR, R, BW. B and LW. (where L is the symbol for blue)

This relay is supposed to be on the right kick panel around or near the heater box.

Not there as far as I can tell. Took out the passenger seat and glove box so I could examine that area well.

:-(

Well guys, I finally found the OD Relay. You have to remove the computer and drop the heater fan box/plenum to even see it way back in the corner. if I had a smaller file size jpeg, I would post you a picture.

But, all that work only find out that the MD510483 relay is no longer available. Anyone parting a Gen 1?

The relay is anything but typical old style. There is a small circuit board inside that handles the switching. This Part (P/N MB510483 ) is no longer in production. Not surprising since we are talking about a 30 year old truck. Well, I'm one of those guys who like to keep the old one going and I've brought some old ones back to life that others have given up on. That is probably strange to some. To me its challenging and fun.

So, I've by-passed the relay board. Power now goes directly to the solenoid. The transmisssion up shifts and down shifts just like it should. What is lost by doing this is a check to see that the engine is warmed up (signal coming to the relay board from a coolant temperature sensor) and the ability to shift out of OD manually with the button on the shifter. NOT a big loss in my opinion.

Fine to go now ! If, I ever find a replacement relay, I can put the configuration back to stock, but, I see no big rush to do so.

Enjoy your rigs!

I'm parting an 89 LS. If you're in no hurry, that relay may still be in place.