I recently purchased a new tachometer for my '04 Summit 550. I installed it and started the sled before buttoning it back up. The tach needle wouldn't move. I'v installed a few of these things and it's only a matter of plugging them in. I checked the connection and it was snug. I checked to make sure the correct tach. was ordered and the numbers were ok. I plugged it back in and thought I had it working. After tightening it down I started the sled one last time. ALL the warning lights in my speedometer were lit but the tach wouldn't work. A second or so later , the tach worked and the warning lights went out. A few seconds later and the warning lights were on again and the tach needle went back to 0. And the cycle continued. Has anyone else experienced this and if so. could you provide an explanation as to what's going on ? Thanks !