new hardin gauages
 

looking for suggestions....
i just put in new hardin gauages, and the oil pressure is not correct.
the motor has two oil pressure electric senders, asl i understand it, one is for alarm, that would be the sender in front main area, other which is above oil filter is for the gauage.
so , my thought was , i kept old sender on front main , as i have same old alarm , and replaced oil filter sender with new sender for new hardin gauage.
first , when i primed this motor , i put on a mechinal oil pressure gauge and had 60 psi when priming,
now fired new motor (547), oil pressure gauge says 30 psi....???
so i disconnected front main sender, i thinking it was old and was not working with new gauage, then re fired motor and gauage showed zero.....

so ,,,,,i am thinking to replace old sender with new sender also , as i did for sender in oil filter area.

any suggestions???
is my thinking correct,,,then i would two new oil senders for the hardin gauges.
i mention harding as the boat had vdo gauges...its an old scarab


thanks
flash.....

anyone??????