I was driving into work this morning and my car started beeping out of the blue. It's never beeped before, so that worried me. Then the tach dropped down to 0 and stopped working, but the car continued to run beautifully. I've heard that the tachs on these cars can be touchy in the cold, and today we got our first real cold snap of the year, but I've driven this car 3 winters in the snow and never had a problem with this before. I popped the hood when I parked and everything seems to be in working order, so I'm kind of stumped.
Does anyone have any other suggestions as to what the problem might be? And is it ok to drive it, or could there be some other underlying issue that would cause problems when I get it back out on the road? Like I said, it ran beautifully the whole time (aside from the annoying beeping), but I don't want to chance wrecking out on the side of the highway in 2 feet of snow

Please reply here or via email @ barndirt@hotmail.com. I may not be able to get back on the forum today to look :S

 

I believe the tach operates on a signal from the trailing coil. Look there and check for faulty connections.

 

The connections look fine, which is part of the reason I'm so stumped. There are no loose/bad connections or fuses.

 

It's either the harness at the trailing coil (remove the plug, clean both sides, apply dielectric grease and reassemble) or the tach itself. However the beeping is from the power steering computer which also gets it's RPM signal from the trailing coil so the failure is likely at the coil or harness.

I've never heard of any RX-7 tach being "touchy" when cold.