01-05-2022, 05:42 PM
Jeff,
Your fan control system appears to be the same as mine - at least your pictures show all the same hardware. Fan theory is pretty straight forward - the fans will have power available with ignition on, but will only energize if the thermal switch (the largest round black sensor closest to the engine in the back of the reservoir- 4th picture) reaches 160 degrees or so
and closes the control circuit to the large relay in the rear compartment, sending power to the fans.
My thermal switch failed, and since draining the tank didn't sound like fun at the time, I simply bypassed the failed switch allowing the fans to be controlled by the ignition until I could do a proper repair. I would guess maybe your extra switch is a work around for a failed thermal switch.
As far as fluid, I refilled my system with what the original owner used for many years- Napa 75206 ATF 4. Which is a synthetic transmission fluid - I believe a Chrysler specification.
Your fan control system appears to be the same as mine - at least your pictures show all the same hardware. Fan theory is pretty straight forward - the fans will have power available with ignition on, but will only energize if the thermal switch (the largest round black sensor closest to the engine in the back of the reservoir- 4th picture) reaches 160 degrees or so
and closes the control circuit to the large relay in the rear compartment, sending power to the fans.
My thermal switch failed, and since draining the tank didn't sound like fun at the time, I simply bypassed the failed switch allowing the fans to be controlled by the ignition until I could do a proper repair. I would guess maybe your extra switch is a work around for a failed thermal switch.
As far as fluid, I refilled my system with what the original owner used for many years- Napa 75206 ATF 4. Which is a synthetic transmission fluid - I believe a Chrysler specification.
David and MaryLynn Kammeraad
1996 Newell #427
2014 Buick Lacrosse