I have a CRX EE8 EDM 1991 B16A1 OBD1 p30, with a s2000 AP1 cluster and ktuned dash converter.
my issue is with the coolant temp gauge - my sensor is 37750-ph2-014 ( coolant temp sending unit 1 wire )

37750-ph2-014 sensor readings and steps:
01)4000mV
02)0370mV
03)0124mV
04)0093mV
05)0086mV
06)0072mV
07)0062mV

the problem is when i turn on the lights ( or other electric device ) my voltage sensor readings will decrease +/- 50mV
so if the coolant temp gauge its on step 3 ( +/- engine 87ēc ) and if i turn on the lights my gauge will move to step 4 ( forced my the lights on and not by engine temp )

how can i stabilise the voltage , so that the electronic devices ( lights, electric windows... ) will not change it ?