Greetings!

New member, first post, first Volvo.

1990 245DL, 5-speed, 200k. I have owned an 80s e28 BMW so I am familiar with Euro cars to a degree.

I just installed a tach in place of the large clock and also added a small clock in a blank next to the radio. Everything works except my speedo above about 32 mph. It just stops at that point and picks up again when I drop below 32. All connections are tight. I even unhooked everything a second time and connected it back up.

One thing I did was flip the switch on the back of the speedo that the button on the lower right corner controls. What is that thing? It seems like a reset of some sort. I then flipped the switch back into it's original position.

What's going on here?

 

the button that protrudes is a mechanical reset of the trip meter. the button thats recessed resets the 'service required' 5000 mile timer.

your speedo might have some flakey solder connections on its circuit board... the fix is to 'reflow' all the solder joints... if you don't have experience with electronics circuit board soldering, would probably be best to find a geek/nerd friend who does and who has an appropriate temperature controlled soldering iron

 

I am going to check the L-plug that is held on with the clip on the back of the speedo. When I first tried to pull it off, I pulled in the wrong direction thinking it came out 90 degrees to how it was supposed to come out. Maybe I pulled the contacts apart a bit. I'll retension them as in this pic.

 

when you did that, you likely flexed the PCBA (electronicese for printed circuit board assembly), and this could quite likely have cracked a soldered connection on the board, these cracks are often invisible. reflowing every solder joint on the board will usually repair such damage

 

I found another thing. Instrument lighting does not work either.

 

instrument lighting is a /completely/ different circuit than the speedo.