Help please! 2005 Sienna Rear Defogger not working.

[Shagger]

All,

Need a bit of help. My rear defogger in my 2005 Sienna is not working. The wires don't even get hot. I checked the fuse #43 and it seems fine. I see that there is a Defogger relay in the fuse box in the engine compartment. Is there a way to test the relay that I have and see if it's good? Anyone have any ideas on what to check next?

Thanks in advance!

[dandaman]

You can try to swap the relay with a known working one. You can also bench test it by taking a 9V battery and applying it across the coil terminals, if it works it should click.

[Shagger]

It looks like there are 5 different spade type connectors on the relay. Which are the coil terminals?

http://www.autopartsnetwork.com/cata...=model:Sienna_

[dandaman]

Not sure but the relay should be marked, it will be the 85 and 86 terminals. If not this diagram should help you identify them:

http://www.the12volt.com/relays/relays.asp

[Shagger]

Thanks Dandaman - I will try that out tonight when I get home from work! Hopefully its the relay and will be a simple fix...

[Shagger]

I touched a 9 volt battery to the 85 and 86 terminals of the battery and it clicked. Ugh. Back to square 0 I guess? Can anyone think of something I am missing?

[dandaman]

Can you hear the clicking while it's installed and someone is toggling the switch? The defogger is a pretty simple deal, you have two points of failure:

1. Input into the relay (Body Computer powers up the coil)
2. Output of the relay (Fused power to the defogger).

#1 is easy to rule out by hearing it click installed. #2 is a little more tedious and takes a volt meter and probing the various connectors.

Looking at the wiring diagram ( http://minivanclub.org.ua/info/Sienn...i/062fwdrw.pdf ) there are a couple of junctions to test out.

I'd also do a visual check of the connectors to the wire array on the back glass and make sure they're still connected. That's been the usual point of failure for when I've seen defoggers go out. That said, I haven't looked too closely at my (new) Sienna but I'm not sure exactly where those are at.

[shortlid]

If the thin wires that make up the grid are broken that would not allow it to work. Many times the stickers that are affixed to the inside of the rear window when removed damage the grid.