Hi all! I have a 1988 240. Had to replace the plastic gears for the odometer (which went fine). Trying to get it all back together. I drew a diagram of where all the wires go, maybe not good enough. Does anyone have a pic or drawing of where all the wires go? I know about the white/red tach wire that should never hook to the 2 prong speedo. But now the overdrive light is on & so is the battery light????? Any help greatly appreciated!!!!!!!

 

Ok figured out where everything plugs in except for the orange wire. Can anyone please help??

 

Apparently that is the overdrive wire for that year. On a 1993, it goes over the pin on the bottom left, just left of the last idiot light bulb, all when you are looking at it from the back like the pic. Should be connector size specific.

Sorry the diagram is sideways.

 

I'm looking at the greenbook wiring diagrams for a 1987-88 240... the OD wire is labeld as yellow-red and is on its own single spade lug connector at the far lower right (left if you're facing the back of the instrument panel).

the only orange wire I'm seeing is for a MANUAL overdrive as the upshift indicator, and its pin 4 of the big circular connector 31.

 

Thanks for the replys!! I am now almost certain the orange wire wasnt even hooked up to anything. This car has so many wires & plugs that go to nothing . During my research I also read that there is supposed to be a single yellow wire for the cruise control which is not there no wonder it doesnt work. Well there is one, but it seems to go from the fuse box to the radio (aftermarket). Then I went to replace the clock b/c it didnt work & there was wires coming from the back of it but the connector was not plugged into anything & I cant find anything that it would connect to.

Come to find out the speedo workes basically when it wants to. The odometer gear was definately not working, not just missing a tooth, but disentegrated into pieces. It doesnt seem to be working after replacing it, but I did read that it could take some driving time to get it kick in. I havent been able to drive it hardly at all. So now all wires are where they should go I have to figure out the speedo problem & cruise would be nice.

 

speedos go flakey due to leaky capacitors, or a failing chip on the circuit board. also the wire at the speed pickup in the differential can corrode and become erratic.

 

When replacing the odometer gear, make sure you got all of the old remnents out. Many times the broken teeth remain in the works there and jam things up. Also, check the solder joints on the little motor that runs the odometer. I have seen pics online of cracked solder joints here. A little touch up with a soldering iron should fix any of those.

As far as the cruise control is concerned, it should be connected to the double spade lug. If you find the correct wire, that is where it goes.