I have the aux. tranny cooler mounted under the port side of the bed. It appears to have a fan, but I question whether it's working or not. After a good romp up a long grade (ambient was 95*!) Saturday, the temp gauge registered 220* for 5-7 miles *after* I backed off and set the cruise. Once stopped in traffic, it went back to 185*, but didn't seem to be happy until I slowed way back. The tranny was just serviced and I was completed unloaded.

I assume the fan controlled by a thermostat? (rather than the OEM temp sensor pulled for the Isspro temp guage )
T-stat is mounted where? Should make at *what* temp?

Is the fan fused?

Planning to yank it all out for a cleanup & test prior to my first haul next week and wanted to get everything straight beforehand.

 

The thermostatic switch is mounted on the side of the cooler itself. I installed a switch to control mine manually.

 

You can definately hear them run from the drivers cockpit. Similar to clutch fan noise, just coming from the other end... Mine turns on frequently when towing on hills, but seldom empty. (sorry, I dont have a gauge) but I think it is set pretty low (180F?)

 

I have the aux. cooler in the same place, but the previous owner must have put a switch under the dash by the E-brake release. I do have a Trans. gauge and I just keep an eye on it and it never seems to get over about 185-195 with or without the fan on. Just to be safe when I am towing, I turn it on. You can hear it when its on. Its not to loud, but you can hear it.