240 Overdrive problem

I've got a '91 240 wagon with an auto box which doesn't seem to go into overdrive.

The button on the side of the shifter does nothing to the engine speed and the 'overdrive off' dash light doesn't light at all - either when the button is pressed or when the ignition is turned on and all the other dash bulbs light.

At this stage I am suspecting the relay as I cannot hear it clicking when pressing the button - but if the relay was broken would the situation be that overdrive couldn't be engaged, or that it couldn't be disengaged (i.e. it was always on)? If the overdrive was always disengaged (as it seems to be) wouldn't the dash light be permanently on?

I guess the relay and the dash light could both be broken?
1992 240 Wagon, Adelaide

My blog: https://avolvoinadelaide.wordpress.com/


  • It does sound relay related.
    I think I might have a spare relay if you're interested? I can check tonight
  • What RPM are you seeing at 100km/h? Are you only getting 3 gears, or 4? A video might help.

    There's a solenoid on the side of the transmission which commonly fails, but as far as I know it only controls overdrive lockout. This means you'll get all 4 gears when it's failed.
  • Not sure about RPM at 100 - it's quite a way to the nearest 100km/h road. Will have a drive tonight and note down some figures. I'm pretty sure it's only going up as far as third but will double-check tonight.

    240 - if it does turn out to be relay-related then would be interested if you've got a spare :)
  • jamesincJames (@jamesinc) Oz Volvo Ice Fortress
    I believe with the circuit unpowered you would lose fourth gear. I seem to recall a few years ago I did a conversion from a 3-speed auto to 4-speed, and initially I didn't have an overdrive button, so I wired the solenoid to the ignition so it would have constant 12V and allow 4th gear engagement.
  • I went for a quick test drive last night – I definitely can't hear a relay clicking when I press the overdrive button on the shifter with the ignition on. The button has no effect on engine RPMs at any speed, nor does it cause the dash light to come on when pressed.

    I could only road test up to 70km/h and I definitely only have three gears up to that speed – overdrive does not kick in at any stage. At 60km/h the engine is running at around 2000RPM.

    What do you reckon? Start with the relay and go from there? I haven’t checked for blown fuses - is this a fused circuit?
  • It is definitely a fused circuit, I'm pretty sure a wire goes straight from one of the fuses, to the relay.
  • IPD sell an overdrive solenoid bypass plate that will likely solve the problem, but you won't be able to lock out overdrive anymore with the button on the shifter. I never used that button anyway -- the AW70 shifts responsively enough such that you shouldn't need it. If crawling down a very steep grade you only get good engine braking in 2nd, so the button is no use for that either. I use 2nd on the steepest spots descending Mount Tamborine on Henri Roberts Drive, but long steep mountain descents are a rare thing for most of us in Australia.
  • Cheers all - I'll start with taking a look at the fuse box and, if all's good there, move on to the relay. @240 if you do find a spare I'd be interested :)
  • jamesincJames (@jamesinc) Oz Volvo Ice Fortress
    the AW70 shifts responsively enough such that you shouldn't need it.
    Engine braking in third is great on the mountain highway passes
  • I'd like to retain the switchable overdrive function - I've always found it useful on other cars.
  • @Llessur I had a quick look for the relay but haven't been able to find it, I'm sure I have one though.
    Just to confirm, is yours white? (Should be located behind the drivers side kick panel)
  • edited November 2018
    @240 No worries if you can't find it - I'll have a hunt for the relay this weekend and let you know the colour.

    Is the relay behind the kick panel? I've read quite a lot that says it's behind the glove box...
  • I'm pretty sure that's the fuel pump relay behind the glovebox. The overdrive one is behind the centre console kick panel on the drivers sides or at least mine was.
  • jamesincJames (@jamesinc) Oz Volvo Ice Fortress
    I agree with @240 it's usually behind the kick panel
  • Cool -cheers for the heads-up. Could have spent a long time hunting for that one!
  • Ex850RSnoopy (@Ex850R) Somewhere Over the Rainbow. Melbourne.
    Is it worth putting in a very old relay?
    Surely there is a DIY on putting a new one in?
    cancer sucks
  • New would probably be better but from a preliminary search finding one in Oz might be a bit difficult. They’re readily available from the US but they’re not particularly cheap. IPD wants around 50 AUD plus international postage.
  • Sandwood trading in Melbourne keep all the various 240 relays in stock 03 9898 0314
  • Cheers @timbo - will give them a shout
  • jamesincJames (@jamesinc) Oz Volvo Ice Fortress
    What's the part number, I'll check my relay box
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