Speedo Issues

hi guys.................


N Reg Import Waggon

I have today installed a TurboTimer with Gear Change light. also a new boost gauage

Drove the car and npticed the Speedo was not working and i did not think any thing of it untill i put my foot dowqn to test the gear change light that i had set at 5500rpm. The car souned as it had hit the limiter and the Engine Check Light came on. I again boosted to 4500 as before and the car did the same. I got back and reomved the clocks and it looked as if the speedo cable had fallen off. I re attached and make sure it sat as it should when i put it back in. The car then said i was doing 100mph when i was a junction and the needed jum,ping accross the speedo face. ive had it on and off 3 times now just wondered if any oen can help or say that the speedo not been linked would cause the issues above?i know it has a small round silver device that sits on the clocks and then onto the wire for the speedo so i assume this is the converter

Please help

AG