Cooling System and Temp Senders.
I'm posting info, photos, identification, etc on 22R-Eliable Cooling System and Temp Senders.


YOTARICK'S 1986 (I think he doesn't have stock coolant thermo switch (TSW-4WD) so I cropped the photo.


Actual Coolant Thermo Switch (TSW-4WD) on my 1986 22RE.
I verified that Coolant Thermo Switch (TSW-4WD) does not affect starting in normal conditions. I think this comes into play when coolant reaches a certain temp limit.



IMPORTANT: Coolant Thermo Switch relies on bare, shiny metal contact on mounting threads for grounding.

TIP: If re-doing the harness, take the wire for this out of the harness under the intake manifold and run it along the CSI timer switch and ECU Coolant Thermo Sensor; That's where it belongs, and you get less clutter under the already tight space under the intake manifold.


Coolant Thermo Sensor (THW) is connected to THW and E2 of ECU using same color wires in 1986 and in 1988 22RE.
Coolant Thermos Switch (TSW) also connected to ECU TSW using same wire colors.
Safe to assume it's same in 1987 22RE.


TEMP SENSORS CONNECTED TO ECU - 1986 MoreFunner

TEMP SENSORS CONNECTED TO ECU - 1986 MoreFunner