Logo
FULL SITE MENU

Overheat and ECT sensors

T

Tegweni

Regular Contributor
Iam a bit confused here lets take for example a 225hp what is what here out of the 3 sensors ,the 60hp pre 1997 and a 90hp not sure of the year one of the 3 sensors fits these motors as well and the manual refers to it as a thermo switch sensor and the manual of the 225hp refers to the 3 sensors as ECT Sensors so this tells me one of the 3 sensors used on the 225hp is a thermo switch sensor because its used on the 60hp and 90 hp where they refer to it as a thermo sensor if you do a cross reference check you will notice the part no are the same .
 
All the EFI motors use the same thermo sensors and will give you values if read with DrH. All carburetor engines use thermo switches which are on off switches. The only exceptions are the BF135 and 150 A4's which use two different sensors but again, both will read values in volts or degrees C or F and the odd one (91307-PK2-005) is no longer available and supersedes to 35673-ZY3-003 with the use of an adapter harness and new style timing cover to come in line with all the EFI temp sensors, so now one part number fits all the EFI's. Hope this helps
 
Ok thank you ,now i need some help because iam trying to educate myself from what i understand these ECT,s are NTC Thermistor,s and if the motor temp goes up say for example to over heat NTC thermistor,s decrease in resistance as temp goes up and then when this happens the voltage goes up ,now voltage to the ECT when its cold is 4.30 to 5.25 V .the conclusion i draw from this is that the voltage then increases to 12v from 4.30 -5.25 . am i right or wrong here please help
 
All the EFI motors use a 5v reference, ambient temp is usually around 1 volt increasing with temp to 5 V which will activate alarm. All the carb motors use 12V.
 
Back
Top