I have a 3406E Cat Sn 6TS21730. I am working on the thermostat housing and have 2 single pin sensors in the upper housing, that I am looking to replace, so far my parts supplyer has sent a 3 pin senso that, I think is a temperature sensor located elsewhere in the system, and a gasket that is not correct. I have spent time on Cat Parts and SIS and am getting lost in the weeds, must be a peterbilt OEM Option?
It appears that way. Everything I can see on the electrical system for that Serial Number are 3-wire sensors. Single wire would be a sender rather than a sensor. Does the temperature regulator housing have a Part Number cast into it by any chance.?
Those sensors are not Caterpillar. They are truck manufacturer OEM. Maybe for the fan clutch, maybe for the temp gauge in the dash. They may not even be sensors. One is probably a switch, the other a thermister. That’s how it is on the 3406E in T-601 in my avatar.
Correct--either PacCar, Freightliner or what ever. The fan switch is normally located horizontally at bottom on stat housing just above water pump housing.
I assumed the computer switches on the fan? There is a 3 prong sensor horisontally in the lower housing, and 2 single prong senders in the upper part of the housing.
On a E Model Pete here one was for the gauge. Easy to figure with a test light. The other was for the fan clutch and I cannot tell you if that went through the ECM. Your local Pete dealer should be able to get those senders by the year and last 6 of the vin.