This one has me scratching my head. I purchased this old 2001 for a good price, put a Dorman battery in it, and am really pleased with the outcome. However if the weather gets warm I get the P3077 code with the dreaded orange triangle. The battery fan is fine and tests OK when powered up by an external voltage source and the battery fan switch tests ok (if looks as if it's new). But darned if I can find the battery blower motor controller. I've got all the necessary files from Toyota Technical dept and it clearly shows the controller located in the drivers side rear fender. Nothing there. No plug, no mounting hardware etc. I'm not sure where this thing is hiding! Can anybody shed some insight?
Battery controller operated the fan the last time I checked. But I don't have the car and manuals any longer. Bob Wilson
Looks like you're on the right track! I took a look at Diagnostics Manual (RM771E) and on page DI–301, it indicates to check: the Fan fuse in the Engine Room Junction Box, the wiring harness, the fan relay, and then the blower fan. If these are fine then the problem is the Controller. To easily see this part search for images of its part number: 87165-41010. Also this exploded view diagram might help: http://parts.villagetoyota.com/images/parts/toyota/fullsize/822276.jpg The Wiring Diagram (EWD414U) indicates it is between the battery ECU and the Blower Fan. Follow the Light Blue wire with Red Stripe from Pin 9 of the B18 Battery ECU Connector (12-Pin) to the B16 Connector (4-pin) that plugs into the controller. Best of luck, check u-pull-it junkyards to get it dirt cheap.
Usually the blower motor controller will be located downstream from the fan in the vent ducting. Or as previously suggested, try to trace the wiring from the fan motor to the motor controller.
