Hello,

So I own a 1990 Volvo 740 GL (Swedish Model for U.S. Import). Unfortunately, when I inherited the car, the odometer was not working (It is the Yazaki Cluster. No. 1398736). It stopped at 68,115 miles. I took the speedometer/odometer out of the instrument cluster, proceeded to lightly oil it and use an air can to try to dislodge anything, and reassembled the instrument cluster. Sure enough, it started working again... for eight miles. It stopped again at 68,123 miles. That being said, I'm fairly confident that the motor and the gears are intact (any advice on how to access them to make sure would be appreciated). I'm concerned it might be a wiring problem with the connection to the ECU. Is there any way I can check? Does anyone have any other ideas on what the problem could be?

Also, is there any way to find out what the actual mileage is? Is there some kind of back up odometer I can check?

Thank you!

 

there's no backup, only the mechanical odometer in the dash.

to take it apart, you gently but firmly pull the needle off the speedometer, then the speed+odo module can be removed from the speedo faceplate, and you gain access to the mechanism

before removing the needle, carefully lift it over the pin stop, and check where it comes to rest, note the exact place. so when you put it on you put it back in the same place, then gently lift it over the pin stop. that pin stop is rather fragile.

 

Hi, I have an '88 and '93 240s. Both had issues with the odometer. The odometers in those cars have nothing to do with the ECU, but a sensor on the axle. If the speedometer is working properly, then everything is OK from the axle to the instrument cluster and your problem is in the cluster. This is assuming that the 740 is similar to the 240. Go to Odometer Gears - WELCOME. They have a procedure complete with pictures for the 240. You can look to see if it looks like yours. There is a plastic gear which always loses a tooth in these odometers. This is a $25 gear which is a cheap piece of plastic the size of a dime. If yours is the same, then you can inspect that gear.

I also found out that there is no need to remove the odometer needle. I'd rather not do that and run the risk of breaking it. If you are careful, you can remove the rear cover and dissemble it as described on that website without removing the needle.

If you find that there is nothing wrong with the gear, then you need to get a magnifying glass and carefully inspect all of the soldered connections for a "cold solder joint". What that means is one of the wires that protrudes through a hole in the circuit board that is supposed to be soldered has fractured and with a magnifying glass you can see that there is a tiny space of nothing completely surrounding the wire so it essentially has no connection. It needs to be re-soldered.

Good luck.

HG

 

240 speedos are NOT like 740/940 speedos, quite a different animal.

The 7/940 speedos are in 99% of the cases affected by the capacitors inside the speedo heads which go bad and have to be replaced which is a fiddly procedure with questionable success rate especially when performed by amateurs. If the pick up wires at the rear end are not broken, then the problem is in the speedo itself.