Have an '88 240 (auto) volvo giving me problems with the overdrive...

Took it in for the NY state inspection with both backup lights not working. The mechanic tried to fix it but wasn't able to and did something to the overdrive (he wont tell me what...since it would mean that he admits responsibility) so now the overdrive wont kick in (never had problems with it before). Took it in again to try to get it repaired....so now the little overdrive light comes on (no click) when the car is in park but the switch doesn't work whenever the car is in something other than park.

My guess is that the wire that goes to the solenoid was broken/cut by the mechanic (since i think the wire comes close to the backup lights wire and I've already replaced the relay) but i dont really understand the deal with the switch...

any input would be great....dont want to take it to a shop again

thx

The wire for back-up lights doesn't come from the (auto) tranny. The switch is in the shifter, along with the Neutral/Park safety switches. I don't believe it goes under the car at all (no reason to).

Your mechanic may have done something to the solenoid wire though. The circuit outline and summary below may help you analyze the problem.

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OD operation involves 5 components and the wiring that connects them...

1) Fuse 11 (200) or 12 (700/900) supplies voltage to items #2, #3, #4, and #5

2) The Shifter button/switch turns the OD relay off and on

3) The OD relay controls the Upshift (not "OD") Arrow light and Solenoid (separate wires)

4) The Upshift Arrow light ON means the relay and OD are OFF

5) The OD solenoid allows OD engagement when ON, (the "default" Relay state at Key On)

If the Shifter switch turns the Arrow light (#4) on and off, then items 1, 2, and 3 are OK, and the problem is most likely the undercar wire to the Solenoid (#5) or the wire connector terminal at the solenoid.
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There should only be two wire going to the tranny/OD...the back up lights and the one to the solinoid to activate the OD. He may have cut the solinoid one thinking it was the other. OD is in the rear of the unit and the back up is on the tranny.
Just check to see if there both still attached.

OK, I think the state Inspection guy messed around in the shift lever housing box. From the passenger compartment. Not at the tranny itself. Switch is not there, if I understand right.

MY GUESS is that he went into that box to attempt to get the backup light switch to work, and instead messed up the OD wire.

Auto tranny car here.

The shift lever housing has a mess of wires, including, I believe:
the shift indicator lite
the backup switch
the neutral/park safety switch that requires those settings to start the car.

Also in that area is the wire into and out of the OD switch on the lever, that wire goes up to the relay behind the glove box. Signal goes TO the relay by that wire.

The relay sends current (or not) down via another wire - that wire passes through the shift box without any terminal there, down into the tranny tunnel, and goes to the solenoid at the tranny. It exits the shift box via a grommet at the front. DON'T remove the grommet. Never will go back in.

Look in your shift lever housing. You remove 2 screws at the front and slide the plastic cover out of the way. Removing entirely is not in my bag of tricks.
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[aka Sophie's Maintainer] Sven: '89 245, IPD sways, E-fan conversion, 28+ mpg - auto tranny. 850 mi/week commute.

According to fcpgroton's relay listings,
85-93 240s with Auto Tranny all take the same relay; it's white.
So if you're swapping with a friend or from a junker, stay away from standard tranny cars, or pre-'85.

I've seen two types of these white relays, interchangeable.
If you open it up and look at the innards, one version (apparently later) has a printed circuit board where you can see the printed circuit sealed, apparently, below a layer of protective material. The other one has solder lines applied directly to the circuit board that create the "wiring". Probably more prone to failure.

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[aka Sophie's Maintainer] Sven: '89 245, IPD sways, E-fan conversion, 28+ mpg - auto tranny. 850 mi/week commute.