More Rev Counter Questions In A D Turbo

[yeti-dj 7]

Hello, havins some problems with the rev counter in my little diesel i recently changed to the clocks that have the rev counter as mine didnt which all went well but noiw a bit stuck.

 

Initially the rev counter worked but seemed to go at half the speed of the engine, engine 1000rpm-clocks 500rpm, so in a bid to fix this i have now got it to not work at all, pants....

 

1- is there any way that i can check that its not the rev counter in the dash thats at fault?

 

2- is there any way to check that the sensor is putting out the correct signals?

 

3- do the diesel have a fuse that could be blown that the rev counter needs?

 

4- the sensor i have has 6 little tabs on the bottom of it,i take it just push the sensor in til these touch the flywheel?

 

thanks for your help, beginning to really hate this car........