I have a 91 740 Turbo wagon. The overdrive is not working. The overdive over-ride switch and lite both work. This was an intermitent problem that is now a hard failure. One side issue - the speedometer is not currently working - could this effect the overdrive?
Thanks
Lee

 

No the speedometer is a separate issue. I think if the light is out and there is no switching into overdrive that you have a bad switch or a bad relay.

 

The switch and light are good (i.e. the switch toggle the light on and off but with no effect on the overdrive function). The electrical diagram ( from alldata.com) shows a connection from the speedo to the relay.

What exactly does the overdrive solenoid do? Does the transmission determine when to shift into overdrive? [If so, does an energized solenoid enable or disable the overdrive function?

Thanks for any help.

Lee

 

I assume this is an automatic? There isn't a connection between the speedo and the OD function. The OD circuit for the 240 and the 740 is generally the same (minor difference regarding the light and which fuse is used).

When you turn the key on, 12V is applied to the OD solenoid through the realy. It retracts and allows fluid to flow between two small holes in the transmission, and allows shifts into 4th gear around >40 MPH.

When you push the button the arrow in the cluster lights up and power is removed from the solenoid. The passage of fluid between the holes is blocked and the OD fuction is turned off.

So if the OD doesn't work its because power isn't getting to the solenoid (fuse, relay, or exposed wires), or the solenoid is broken, or you have a problem with the transmission fluid.

I permanently enabled OD on my car by grinding a channel in my non-functional solenoid. IPD sells a kit that does the same exact thing.
http://www.ipdusa.com/Volvo-200/Tran...-266-672-1891/

Note that the OD function is inverse between autos and manuals.

 

Bubba, I have a '90 240 DL. The overdrive stopped working completely but the light on the dash and the relay are both working. Checked the fluid and was half a quart low. Re-filled to proper level and replaced the OD solenoid with one from the used parts emporium lol. Now the OD is working but doesn't kick into 4th until around 60 or 65mph. Before it would kick in by 40 or 45mph at the most. Do you think the trani is damaged or maybe need a new OD solenoid? Thanks Jim

 

I would flush/replace the fluid if it hasn't been done for awhile.

 

Hey, I have an 85 244 GL and yesterday had this weird smell on the way to work going around 30mph. Hot/burnt? and then it was gone. When I started my car to drive home OD light on dash is on and car won't shift into 4th. Which fuse do I check and where is the relay for this model.

 

Don't forget the overdrive relay, known for issues as they age. Overdrive soleniod is often a culprit, fluid issues can affect them. I once lost overdrive in my wagon for ashort while when towing a boat, fluid overheated a little and possibly foamed resulting in no overdrive.

Regards, Andrew.

 

Light comes on even if overdrive button is in the overdrive position. Also you can here a faint noise like a relay noise. Where is the relay for this OD?
Thanks John

 

The relay is the first think I check. It's under the radio where all the other fuses are...

 

Yeah, I finally figured out where the noise was coming from. I have quite a time with locating noises as I wear hearing aids and the receivers hang over the back of the ear. Makes everything sound like it is behind you.
Anyway, got any short cuts for finding a way into that part of the dash? My fuses are along the door post on the driver's side of the car.
I will probably try to find a YouTube video on it as well.
Thanks
Gus

 

if your fuses are on the left side of the driver, you must have a 240, not a 740/940... on a 7/9, all the fuses are behind the ashtray, while on a 240, they are scattered all over.

on your 1987 240, its accessible by removing the glovebox, and its basically tucked in behind the center console air vents.
http://www.davebarton.com/pdf/relay_87_240.pdf <= relay location diagram.

the original OD relay looks something like this,


replacement:
https://www.fcpeuro.com/products/vol...60-780-3523804

 

Pierce, I apologize; I should have stated the model of the car. Yes, you are right. It sounds like the noise is coming from behind the radio or climate control.

 

you can test if the overdrive relay is working by taking it out and jumpering pin 15 and 87 with a paper clip. does this allow the trans to shift into 4th gear? if so the relay is bad.