temp gage not working after replacement please help

i have recently bought a bronze mk1 convertible Karman clipper she is Mint and very lovely but had to change the hose housing …. where the sensors are !!!!

After replacing my old heat sensor housing where the water pipes runs to , there are 2,3 clip connectors. the 2 on top have been cleaned and re-seated with blue slicon gasket sealer. … now all back together my heat gage is not working can anyone help as i am well and truely baffled…