OK, I'm slowly sorting out a few annoying problems with the 1989 240. Let's see, since Saturday, I've fixed the taillights, transmission kick-down cable (thanks Tech) and today was introduced to fuel pump relay problems! A good knock on the pavement and that sucker is working fine.

So, I'm wondering what the button on the side if the shifter is and why an arrow on the dash lights up when I press it. I now know that it's the overdrive select button. Trouble is, nothing happens when I press it, other that the light on the dash.

I know that the overdrive solenoid on the tranny could be the problem, so I'll check that out first opportunity, but I'm thinking that there is probably a relay associated with that circuit as well. If I can find it, I'll work my magic on that dewd too.

Is there a relay for the overdrive circuit? If so, where is it?

Thx

 

If the arrow on the dash is working with the switch then the relay is working fine.
If the relay was bad then the arrow would stay on all the time.

When the arrow is off check for power at the soleniod on the trans.

 

Does the vehicle have to be in drive while checking for voltage at the solenoid?

 

I think it will have power with the key on.Then it gets activated to shift at a certain speed. But you will still have power with the key on.If not then there is a break between the shifter and the trans.That is known to happen at times.