The tach I won was installed, and the wiring problems figured out as
discussed in another thread. I took the 240 for a drive and it was
nice to be able to turn up the stereo and still know what the motor
was doing! BUT... Got out on the highway and saw that the speedo only
would go to about 40mph and that was it! Seemed accurate to that
point, but that was as far as the needle would go.

Of course, all the things I could have screwed up went through my
head- pulled a wire, broke a part of the PC board, left a wrench in
the patient, etc.

Got a chance to get back into it this AM and examined everything as I
pulled it apart. Cleaned the contacts on the back of the speedo (where
the 3 wire, 90 degree connector attaches) as well as the contacts on
the wires themselves. Nothing unusual there. Looking carefully at the
assembly I noticed some cobwebs on the inside of the plastic lens of
the cluster so decided to complete the disassembly and pull the speedo
to clean everything out since I had not yet found anything suspicious.

With the speedo removed I flicked the needle gently and it bounced off
40mph. I repeated it a few times and it went to about 60. A few more
times and I got it to 100... hmmm... I put on my dad's old magnifying
hood/lens thing (what old machinists use to use to read vernier
scales- and no, that's not what you use to weigh verniers). In the
inside, back area of the speedo mechanism where the magnet(?) is, I
could see a loose spring! After some careful cajoling with some long,
fine tweezers and a dental pick I was able to fish it out.

I had already seen where it came from- it was one of the two trip
odometer reset springs. Whether it had just recently come off, or had
been floating in there for years I don't know, but there is no doubt
as to that loose spring being the cause of the speedo error. it could
have been loose for a long time, and when I installed the tach, the
removal and multiple reorientations of the cluster as I worked through
the installation allowed it to get up in there.

Off to fix something else....

__ __
Randy & \ \/ /alerie's
\__/olvos
'90 245 Estate - '93 965 Estate
"Shelby" & "Kate"