My recently acquired 1987 240 DL wagon did not come with a tach. I recently found a 1988 240 GL at the local parts yard so I pulled the instrument panel and 2-inch clock. While at the yard I didn't have any way to record which wires went where. However, when I pulled my panel I documented carefully so that I'm pretty sure everything is hooked up the same.

The parts yard panel was pretty dirty, so I removed the clock and transferred the tach to my panel. The white/red wire was easily located and connected to one of the two spades at the bottom of the tach, and the clock connector from the parts donor re-attached at the top of the tach. I also confirmed there is a white/red wire at the "1" terminal of the ignition coil.

The problem now is that when I turn the key to "on" before starting the car, the "new" tach shows 1500 RPM. When I start the car the tach slowly climbs to 2000 and stays there regardless of actual engine speed. So, I'm wondering have I done something stupid to break the tach, or is it just DOA? The donor car was hit from behind, so I can't imagine what could have toasted the electronics.

Any suggestions would be welcome.
Thank you and Best Regards,
-- Jeff Buckles
-- Aloha, OR, USA
-- 1987 240 DL wagon