DA8 XSI Integra rear defroster not working

ASSISTANCE Stock Engine-Bay Components
1

Hi guys, might be a long shot but I have a JDM DA8 XSI Integra and I’m trying to figure out why my rear defroster isn’t working.

Looking online I’ve seen that the ICU being degraded could cause the issue.

ICU being the issue would make sense since the rear defroster don’t work, I don’t have a key in chime or a lights on chime.

But in saying that my ICU doesn’t look the same as the ones from the states. Firstly it’s blue coloured instead of grey and the PCB looks completely different.

Comparing my Underhood fuse box to amayama. I don’t have a 30a fuse above the 70a fuse. I’ve attached an image of my Underhood fuse box for reference.

1000012927
10000129271200×1600 374 KB

I’m unsure if there’s any differences between other JDM gen 2 integras but any input would be a huge help

2

I can only speak to how the USDM rear “DEFOGGER” works. The ICU sends a signal to the defog relay and the relay sends power to the defog grid. I would locate the defog relay on your car, verify the relay is working then energize the relay and see if the defog works. If that works then start looking for a replacement ICU.

I’ve never seen or heard of anyone doing this but I don’t see any reason why you couldn’t just bypass the ICU defog circuit. All that circuit does is shut off the defog after 30 minutes. Just wire the relay to a switch and don’t forget to turn it off.

3

Not having the chimes could also be due to a faulty door switch. Open the door and press on the switch while your key is in the ignition. Maybe you’ll hear the chimes then.

But yeah interesting that the fuse would be removed. Also @GeoMetry is grandmaster at ICUs. Trust him.

1 Like
4

Yeah I’ll give that a try. I have bought a spare ICU but the PCB looks burnt on the edges. Will have to go the re-engineering route on that one.

Might just have to cut my losses on getting the OEM defoggers to work and buy a rear defogger retro install kit.

5

The thing about the missing 30A fuse is that there aren’t threads to screw anything in. So I’m unsure if maybe there were JDM DAs that just didn’t have rear defoggers?

1 Like
6

If you have documentation about the JDM ICU like this documentation for the USDM ICU then I might be able to help you. But even a brand new OEM ICU wouldn’t fix the problem if the relay or something else downstream of the ICU has failed. On a USDM Integra all the ICU does is provide a path to ground for the relay. To bypass the ICU and test everything downstream from the switch on a USDM Integra is pretty simple.

  1. Verify Fuses 17 & 31

  2. Unplug the defog switch

  3. Turn the ignition switch to the run position

  4. Jump the pin from the YEL/WHT wire (Position 1) in the plug to a known good ground to energize the relay. You might be able to hear the relay click.

    Defog
    Defog203×146 8.12 KB

  5. The defogger should now be on.