88' Volvo 240 Wagon Speedo Occasionally Working
 

So I searched the forums and never found this exact issue....

Occasionally my speedometer likes to drop. Or flutter a little bit and then drop.

It had this problem when I first purchased the car (very used) and at the time the odometer also didn't work. I've since replaced the gear on the odometer (which now works) and the speedometer still has the same issue, so I'm pretty sure the two are unrelated.

There is really no pattern to when it does or doesn't work. But when it does work, I'm under the impression that the reading is pretty accurate. It's either on and completely working, or just completely off.

I'm not totally sure how the assembly of a Volvo Speedo is, so I can only assume so much, but I'm guessing it might just be an old wire?

Oh, and only the passenger side stereo speaker works, so the wiring overall isn't in this best shape. BUT I'm hoping this is an independent wire and not some sort of issue where I'd have to redo the whole harness.

Thanks for any and all advice that you can offer,

Alex

Just my personal viewpoint, but 80's Volvo radios were underwhelming when new...toss it, leave it and don't retrieve it. Still, it may very well just be a bad wire going to the door speaker. If you do conclude it is the head unit itself, I would not waste much time attempting repairs. Today, on eBay and elsewhere, you can buy head units for $75-100 that all the modern features. I don't use CD's anymore...all my music is on jump drives.

The speedo? Usually the issue is at one end or the other. Check the sender connection on the back side of the differential cover. Plugs in and has 2 wires. Check to make certain they're ok. The sensor seldom fails itself butthe wiring can. If that's ok then check the 90 degree connector on the back of the speedometer.

Do your cluster lights flicker when the speedometer drops? If the cluster has been remove a few times, the 90 degree connector that is in direct contact with the circuit board like said, can get loose and any slight bumps or movement can open the circuit.

Ford issued a tsb on the early 90s f-series trucks about a speedo flutter. It called for vss (vehicle speed sensor) replacement. Those were one of the first vehicles ford used electronic vss's in and were run off of the rear diff just like the volvo vss and that was a known issue.

I'd check yours out.

I took the dash apart so many times for the odometer I bet it's just that 90 degrees connector. I think it got significantly worse than it was before I took it apart, afterwards.

So I'll try to get a chance these next couple days to take a look at it.

Is it just a plug-in connect that I need to make sure is plugged in all the way?

Thanks and I'll try to give an update for future educational purposes.

I think checking the connection would be the easiest.