Rear Defroster Issue - Please Help! - Toyota Yaris Forums

Bobohhhhhh · 10-23-2012, 09:16 PM

So I noticed that my rear defroster grid hasn't been working the last week or so. Today I did some troubleshooting and came up with diddly squat.

I did a visual inspection of the lines, despite being underneath tint, look in good condition. I then checked all the fuses... according to the wiring diagram there is a 30A for the Def itself, then a 10A and a 7.5A as well which were fine. I even swapped out the 30 with a new one incase I couldn't see the fault. I then took a voltmeter and tested the connection beneath the 30A fuse and got 11.7 VDC but when I poked and prodded the connections in the rear I got nothing on the meter. Could it be a wiring issue from the front to the back? Or could this be a relay issue? I hear it click on/off as I toggle the switch. Im not even sure where the relay is...can it be replaced?

Im lost please help!

CTScott · 10-23-2012, 10:27 PM

The defroster relay is integrated into the body ECU. Check the voltage on the black wire in pin 2 of connector 4F with the defroster turned on. That is the output from the relay.

10-23-2012, 09:16 PM	#1
Bobohhhhhh Drives: 2007 Yaris Sedan Join Date: Jun 2011 Location: Dover, DE Posts: 3	Rear Defroster Issue - Please Help! So I noticed that my rear defroster grid hasn't been working the last week or so. Today I did some troubleshooting and came up with diddly squat. I did a visual inspection of the lines, despite being underneath tint, look in good condition. I then checked all the fuses... according to the wiring diagram there is a 30A for the Def itself, then a 10A and a 7.5A as well which were fine. I even swapped out the 30 with a new one incase I couldn't see the fault. I then took a voltmeter and tested the connection beneath the 30A fuse and got 11.7 VDC but when I poked and prodded the connections in the rear I got nothing on the meter. Could it be a wiring issue from the front to the back? Or could this be a relay issue? I hear it click on/off as I toggle the switch. Im not even sure where the relay is...can it be replaced? Im lost please help!

10-23-2012, 10:27 PM	#2
CTScott ULTIMATE View User's Garage Drives: 09 5dr LB, 2x 08 3dr LB Join Date: Oct 2008 Location: USA, CT Posts: 13,460	The defroster relay is integrated into the body ECU. Check the voltage on the black wire in pin 2 of connector 4F with the defroster turned on. That is the output from the relay. __________________

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
NEWS: TOYOTA REVEALS ALL-NEW YARIS SEDAN AT 2006 LOS ANGELES AUTO SHOW	VitzBoy	General Yaris / Vitz Discussion	7	09-20-2023 07:50 AM
2012 Nissan Versa	Kal-El	Off-topic / Other Cars / Everything else Discussions	22	06-15-2012 04:48 PM
When will the Yaris hit the showrooms at dealers?	Petrolhead	New YARIS Purchase Forum	181	11-28-2011 07:03 AM
Another rear spring option! Honda Fit springs!!	kngrsll	Wheels, Tires and Suspension Forum sponsored by The Tire Rack	29	10-23-2009 05:02 PM