About 2 weeks ago I asked yall to weigh in on speedometer issues I was having. Thanks for the replies, wanted to post my fix in case others have the same issue.

This was one of my first undertakings with my car so i will post more complex fixes in the future, this is a simple first-timer type-thing.

'87 244- Electric Odo/Speedometer

The speedometer and the odometer were not working in my car so I started at the rear end. I first checked the speedometer sensor in the rear axle while the car was on blocks. Instead of plugging my voltmeter into the rear axle, I started behind the instrument cluster. If I did not have a reading behind the cluster, I would have checked the sensor itself on the axle to rule out wiring issues. The insulation wears down on these wires and can take out your cluster if overly corroded. I found that the speedo head was receiving a increase in voltage as the car accelerated so I ruled everything out from the speedo head to the rear axle. Instructions of checking the sensor are here: http://vol240.blogspot.com/2007_04_01_archive.html.

I took apart the instrument cluster apart and took the speedometer/odometer out of the housing. I did not see any obvious electrical failures and all circuit elements were passing current ok (checked again with my voltmeter) so I took the speedometer motor off the side of the unit. The 25 tooth gear has 4 teeth sheared off so I ordered a new 25T gear (http://www.odometergears.com/volvo.html). This explained why the odometer was not working, but not the speedometer so I knew the 25T gear was not the reason it wasn't reading anything. Both the 25T gear for the odometer and the speedometer are controlled by the same motor. If your odo is busted, but your speedo is working you just need to get the gear. Because I could not find anything wrong with the speedo motor I decided to replace the entire unit (odo and speedo)

I was at my local volvo shop and the owner had an old instrument cluster sitting around and sold it to me for $75. The clock was showing 122K and my car (according to inspections and Carfax) only has 106K. As I wanted the speedo to work, i took the unit with the extra miles. When I got home, I took the new speedo unit our of the cluster replacd the 25 T gear (it was waaay gone) and pluged it into the connector i previously tested to make sure the speedo worked. Sure enough, I was finally getting a speed reading.

Now for the tricky part. I did not want to show an odo with 122K when I only have 106ishK becuase I want to earn every mile on this brick. I found that i could spin the odometer back manually, but as i had 20k to go, it would have taken me days on the couch rolling the odo. I figured out that if you held back the spring that engaged the trip odometer, then both the car's odometer and the trip odometer would go backwards. The trip reset button was the perfect 'tool' to hold the spring back; I inserted the clip that attached to the base of the trip odometer perpendicular to the face of the odometer to hold the spring back. I then took the cutting wheel attachment from the my Dremel tool and put my (now spare) 12 tooth pod (look at the gear website above for a picture) where the cutting wheel attachment was supposed to go. I took the Dremel/12T assembly and put it into my power drill to spin it. I held the odometer unit in place over the 12 T gear and had a buddy slowly start my drill in reverse and the miles started coming off! he took it up to full speed and zip tied the trigger down and miles starting coming off very quickly. It took about 10 minutes to take the correct miles off the clock and I did not have any odometer mechanical issues running from the drill at full speed. I put my new 25T gear and the 12T assembly not attached to the drill and reassembled my speedo unit. Reassembled the instrument cluster and put it back in the car and now i have a working speedometer, odometer and trip odometer!

One word of caution; the first time you remove your instrument cluster, remember and mark which wires attach where. there are 3 female plus that attach to male tabs ont he back of the cluster if you do not have a tach and it is important you put them back correctly or you risk burning out your new speedometer.

Thank for the help everyone! I will try to do write-ups of repairs as i undertake more and more with my new car.

Cheers!