Bought one of the big tach/small clock conversions on eBay, installed in my '89 240 wagon according to directions found here and elsewhere (red and white connector to back of tach, tach installed in dash panel, clock connector plugged in). The tach needle moves when I rev the engine, but only up to about the 1000 rpm mark, no matter how fast the engine's going. And the clock doesn't work at all. Defective parts, or am I missing something? Thanks much.