Randy1121

With it being so cold lately, i've been needing the rear defroster, and its not working. I recently bought the car about a month ago and just noticed this issue. I'm not too great with electrical, but I know basics to it. I've been trying to find other forums either mine is not 100% similar or totally different and I could use some advice where I'm not familiar with hondas AT ALL.

My problem is, I click the button for rear defroster, it lights up, but nothing happens. What steps or what Should I look for to solving this problem?

I know about the relay, but is it in the fuse box in the dash or in the engine bay? Pictures do help as well. Also, it is a coupe model.

Please Help! Thank You!!

tech8

The relay is in the under-hood fuse/relay box. First check the No. 11 (40A coupe) fuse there. The relay can be tested.

Randy1121

Okay, I just checked the relay, had someone click the button for me. the relay clicks over loud and clear.

goldsy

Take a close look at the rear window as well to see if there are any breaks in the defroster lines across the window. You can get repair kits to fix the breaks.

Randy1121

Say if there was one break, wouldn't that not effect the whole window, But only a section? Because I literally get nothing at all to defrost the rear window

goldsy

One break shouldn't have an effect on the entire window. I however know a dumbass who had frost on the inside of his window and took the ice scraper to the inside of it. That didn't end well.

I guess your next option would be to test to see if there is power to the connector right on the window and work back from there.

tech8

At defogger Connector A (at the right C pillar (passenger side), disconnect the connector and with a voltmeter, voltage is checked with defogger turned on. Black lead to chassis ground and red lead to Blk/Yel wire Connector A. (Note: On the rear window, the connector higher up is for the window antennae. The defogger Connector A is a few inches below that.)

Connector B is at the left C pillar, is a ground connector for the defogger.

The connector may be loose or there is a break in the wire back there.

Randy1121

My car does not have a a connector on/by the rear window. I don't have an antennae to begin with

tech8

You have to remove the C-pillar trim panel cover to access them. The antennae is part of the rear glass.

Randy1121

I got you now, Sorry for the misunderstanding. I took off both pillars and revealed this:



Is it possible that the Antennae amp is bad?

tech8

First test for power/voltage at the Blk/Yel wire at Defogger Connector A like I stated in my previous post, with defogger on. If there is no power/voltage at Connector A, then test the Blk/Yel wire at the Antenna Module with defogger on.

Randy1121

I tried and got absolutely nothing from either connector nor the module connector. I'm going to try again tomorrow though with an actual volt meter, not some cheapy one. So i'll let you know how it goes tomorrow afternoon, and thanks, appreciate the help.

Almighty-Si

You can also use a test light. Ground it to the body touch the connectors, you get a light you get power.

You can also use the test light to check the lines of the grid on your rear window.

tech8

If you're not getting power at the Blk/Yel wire in the rear, did you check the No. 11 under-hood fuse like I previously mentioned? Even though you heard the relay click, which is probably the relay contacts closing (a normally open type relay), that doesn't necessarily mean power is coming through the relay to feed the rear defogger.

Report back what you find. There are another area to check if fuse 11 is good and there really is no power at the Blk/Yel wires in the rear.

Randy1121

That's what I originally used, and I got nothing.

Randy1121

I'll try messing with it tomorrow. I assumed if it clicked it works fine, but like I mentioned I'm not very knowledgeable with electrical related items. Tomorrow, i'll report back, Ill switch a few relays around and test from there. I used a test light on the wires and the module.

tech8

The relay may be fine; but, if the No. 11 fuse is blown, power which normally would come from the no. 11 fuse wouldn't pass through the working relay.

Randy1121

Alright, so I got an actual volt meter and tested it, the positive connector A, had 12volts... Back windshield still does not work.

Could coil assembly be bad? Also, my rear windshield is tinted, could that be the cause of the problem? I had a few previous cars with tinted windows and never had this problem though

tech8

Now, voltmeter red lead to Blk/Yel wire Connector A; voltmeter black lead to ground G701 bolt. Is there still voltage? Probably will be.

Next, voltmeter red lead to Blk/Yel wire Connector A; but, this time, voltmeter black lead to defogger Connector B. Is there still voltage?