I just dealt with this problem last weekend on my '84 245. The relay had
been acting up for a long time.
I grabbed another one from a pnp yard and it was worse. All it would do
was buzz and make the OD light flicker.
Finally, I got around to messing with it. The solder joints looked fine
to me even with a loupe magnifier, but the Volvo gurus said to reflow
all the solder joints, so that's what I did. I also used some very fine
sand paper on the contacts, by slipping it in there, applying some
pressure to hold the points together and carefully pulling out the
I put the relay back in and it worked perfectly. Then I did the same
things to the one from the junk yard and it works great too. Now I have
a working OD and a spare relay in the glove box.
The soldering thing really works, even if it all looks good. Not at all
hard to do--well worth the trouble. I feel like I beat the local Volvo
dealer out of 65 bucks twice.
> Thanks to several posts in this newsgroup, I was able to identify the
> culprit behind the overdrive light sporadically coming on, one time
> while driving 70 mph on the highway, resulting in a sudden drop down to
> 50 mph! As I know many of you know, this has to do with a faulty
> overdrive relay (grrrr - not only a lousy design but dangerous as
> Anyway the newsgroup posts allowed me to locate the overdrive relay
> (behind the ash tray), remove it, and pry off the cover. Several posts
> suggested cleaning the contacts and resoldering the joints. These
> looked very clean to me and I solved the problem as follows:
> In the center of the circuitry, there is a small magnet coil and a
> small switch relay attached to a spring. The relay is normally up when
> power is off. When the car is normally started, the magnet is
> activated and the lever pulled to the down position. This seems to be
> what turns off the overdrive. In my case, the relay sometimes seemed
> to get "stuck" and did not make contact in the down position. Since I
> NEVER use the overdrive nor would I ever want to, I simply permanently
> forced the relay to stay in the down position by wedging a small piece
> of wood between the upper contact and the upper surface of the relay.
> This seems to work great and -- assuming you don't need the overdrive
> -- a fairly simple way to solve the problem.
> I'd be interested if anyone has either tried this same solution, or
> knows of a problem that could result. Hopefully this might help
> someone else out someday!