Overdrive relay burnt smell/burnt board
 

Howdy folks,
Long time Volvo owner here.
Currently I've been driving an '81 245 wagon that I'm the 3rd owner of. What a dream!

Anyway I do most of my own repairs & recently my OD stopped engaging, no light on the dash.

This is the M46 manual transmission.
Literally never had an issue with the OD in the 6+ years I've had the car but now....

I've done a lot of research and traced my problem to the relay which I finally found (it wasn't where it was supposed to be!).

The relay is a German made Hella type, I opened it up and it smells burnt & there are some spots on the board where you can see it's burnt.

Now....my plan was to re-solder this thing since I know folks have had luck doing this, but what about the burnt spots? Does that mean it's just fried and I should buy a new one?
The only new ones I can turn up at places like IPD are cheap aftermarket ones....which I don't trust. I'd way rather fix this one!

Any thoughts would be great, thanks.

Mk
https://cimg8.ibsrv.net/gimg/volvofo...36c91669d6.jpg

Typically what goes bad on these relays is the solder cracks and causes intermittent failures. When it is failing it can be a high-resistance connection which generates heat. That may be what you are seeing. Really, what do the components look like on the other side of the board? If one of the components fried then it would need replacement. If it were me I clean it off, re-flow the solder and try it. Doesn't cost you anything to try.

Relay
 

I got you covered if you need any
hit me up at L&D Volvo parts
Atl Craigslist
Got plenty

Goldenblock

Well good news!
The components on the board looked fine so I cleaned up the carbon stains as much as I could & then flooded any pins that looked like they had cracks with solder.

And what do you know! My overdrive is back!

I bought an aftermarket relay from IPD that's backordered, figured it would be a spare that can live in the glove box along with a fuel pump relay.

Pretty pumped this worked, seriously took me like 5 minutes.

Mk