GearHeadDriver

iTrader: (1)

Hey guys,

I've been troubleshooting my rear defroster for several hours now. I have followed the Honda manual on troubleshooting steps. I was able to confirm all the relevant fuses in the car and under the hood were working properly when I checked it out. The relay under the hood was functioning and the defroster button on the inside of the car was illuminating the ON light. I tried to use a multi-meter on the black/green wire under the fuse-box that's located under the hood. I did not get any power. The relay does click though. Just to confirm the relay didn't have a problem, I tried bypassing the relay with some wire on the relay terminals C & D. I then bridged A & B. After I did that, the interior defroster button stopped working, or at least stopped producing the ON light. The relay under the hood also stopped clicking. I rechecked all the fuses relating to the defroster none were popped. I then used a multi-meter on the black/yellow wire that plugs into the defroster button. That wire produced 12V. That wire also goes directly to the relay under the hood, which I checked and it still has 12V despite the relay not clicking anymore.

Just for the sake of troubleshooting, I purchased another defroster button in case I somehow damaged it. I also bought a replacement relay for the fuse box that's under the hood.

I'm trying to follow the manuals and I don't think I'm missing any steps.

What else could I be doing?

Thanks in advance!

GearHeadDriver

iTrader: (1)

Update:

I got power to the rear defroster button again. I swapped the button with a replacement and that got the relay under the hood clicking again.

I still don't know why there isn't any power coming out of the relay to the glass though.

TomCat39

I wish I could look up the wiring in the ETM but all my books are packed away and in storage right now.

I do know there is a connector C590 I think that I was mapping out for another thread that has that black green wire for the defroster in it. There is supposedly two black green wires on the hatchbacks and I am not sure which one is which as only one appears to be documented. I haven't ripped into either back ends on our hatches yet to figure it out.

I would think the defroster would need/have a ground. If that ground were faulty, power would not travel to the defroster.

Wish my books were here at the moment but alas....

Hang on, found the thread and I posted pics of the ETM for that connector:

https://honda-tech.com/forums/honda-...heavy-3287031/

Might not be the solution but maybe it will help you with the trace.

In particular, this photo with ground 553 and all the connectors between.

GearHeadDriver

iTrader: (1)

With the help of a friend, I was able to determine that the under the hood fuse box is bad. There is no continuity from the relay to the underside of the fuse box. My friend/installer is a hundred percent positive this is the reason why no power is going to the window. There is continuity in the factory harness on the power and ground side to the window.

I actually was able to trace the issue back to the fuse box, however I'm not as tech-savvy as my friend so I wanted a second opinion.

What I've done in the meantime is I purchased a used replacement fuse box that I'm waiting on to arrive in the mail.

Hey Tom Cat, where did you find your diagram? I found one online and it looks slightly different than yours.

TomCat39

Mine is from the 1993 Civic Electrical Troubleshooting Manual (ETM) I bought for our cars.

I believe the 95 is slightly different as well as the 92 of course is definitely different.

My wifes is a 93 and mine is a 95 but so far it's been accurate for my 95 too. Not really sure what changed in the 95 from the 93 and 94.

GearHeadDriver

iTrader: (1)

My rear defroster works now. The replacement fusebox fixed the issue.

Rob Waller

Hey I just got a 92 hatchback and I was cleaning up some of the old wiring that was done by the previous owner and the button next to the rear defrost wasn’t connected to anything I was wondering if someone could let me know what it is for thank you for your time