Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror

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Sat 24 Oct 2020 10:01
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - Trawlerman
Hi guys,

Just bought a Civic from 2009, good runner.

Most of the electrics are fine apart from the dreaded fuse 36 circuit. That controls the electric mirrors and also the climate controls and rear demister.

Problem is that one of the mirrors was shattered which looks to have damaged the whole circuit. I tried replacing the fuse but it just blew again.

I don’t care about the mirror controls but the other stuff would be useful. (There is some heating, just not the blowers etc that you need the controls for).

I am guessing there will be a short circuit in the mirrors.

Is it possible to just cut out the mirrors from the electrical circuit and just get the other stuff working? Or maybe better to get a working mirror (plus wires) from a scrapyard?

Cheers
Paul
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Sat 24 Oct 2020 10:36
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - Ian D
If you pull off the mirror cover (the forward facing plastic cover) by pulling forwards close to the drivers mirror (YouTube/Google it) there will be several connectors visible which you can disconnect and retry the fuse replacement. May also be the cables between the door and the car body (ie near the door hinges) damaged or broken/shorting where they move slightly every time the door is opened

Edited by Ian D on 24/10/2020 at 10:39

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Sat 24 Oct 2020 12:07
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - elekie&a/c doctor
Remove the door card and disconnect the multi plug to the mirror . You will still be able to move the glass around by hand . Not sure if this will cure your fuse problem.
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Sat 24 Oct 2020 13:07
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - Trawlerman
Thanks so much for the suggestions guys.

I managed to remove the mirror cover and disconnect everything I could find.

Replaced the fuse again (but see below).

The heating controls are working now. As is the electric control for the passenger-side (ie undamaged) door mirror!

However, when I try the rear demister the fuse blows again.

I replaced the fuse again and the heating control is fine again.

I should have said, I know absolutely nothing about cars!

Basically, the fuses I bought (from Amazon) seem to be really difficult to push in. I have only half pushed them in (so the metal prongs are in, but not the plastic). Fearing that if I push them fully in they might never come out.

Are all these fuses an absolutely standard size? So this fuse that fixes (some of) my problem, it should be fine to push all the way in just like an actual Honda fuse?

Also presumably the fact I have only pushed it halfway, might explain why the demister makes the fuse blow again? Higher ampage than the other stuff, maybe?

Thanks again
Paul
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Sat 24 Oct 2020 13:13
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - elekie&a/c doctor
If the fuse blows when you operate the hrw switch , then it’s possible the fault is with the heated mirror glass . Could be the other door mirror? Sounds like you have the wrong fuses . These take the mini blade fuse that don’t have the extended “legs” . Known as micro low profile fuses.

Edited by elekie&a/c doctor on 24/10/2020 at 13:14

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Sat 24 Oct 2020 13:17
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - Trawlerman
Ok cheers, I will get the correct fuses (plenty of them!) and see what happens to the hrw.

(When I first got the car there was already a blown fuse like mine in slot 36, again halfway out. I should have realised it was the wrong type)

Sounds like I will be doing more mirror re-engineering soon!

Thanks again.
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Sat 24 Oct 2020 13:33
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - Trawlerman
The mirror heating wires, are they the two connectors that plug-in behind the mirror glass?

(I disconnected those on the drivers side mirror at the start.)

Edited by Trawlerman on 24/10/2020 at 13:35

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Sat 24 Oct 2020 14:30
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - elekie&a/c doctor
Yes, the 2 wires to the glass are for the heating element . I would disconnect the other side to confirm the problem isn’t there.
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Sat 24 Oct 2020 14:49
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - Trawlerman
Thanks, tried that, my (wrong) fuse still blows when I switch on hrw.

Will try that again with correct fuses tomorrow.

Sounds like the issue may be the actual hrw though.
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Sat 24 Oct 2020 15:19
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - Trawlerman
Any suggestions what kind of hrw problem might make this fuse 36 blow?

Thanks
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Sat 24 Oct 2020 16:00
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - madf
Any suggestions what kind of hrw problem might make this fuse 36 blow? Thanks

Wiring from car to window move every time the tailgate opens/closes. Probably cracked and broken insulation...

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Sat 24 Oct 2020 16:22
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - elekie&a/c doctor
Fuse 36 doesn’t supply the rear heated glass directly, it’s only a 10 amp fuse . Appears to be a fault with the control circuitry.
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Sat 24 Oct 2020 17:07
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - Trawlerman
Fuse 36 doesn’t supply the rear heated glass directly, it’s only a 10 amp fuse . Appears to be a fault with the control circuitry.

Does the hrw have the equivalent of the connectors used by the mirror glass? If so could I disconnect that and see if the demister switch has no effect, ie no longer blows fuse 36?
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Sat 24 Oct 2020 17:33
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - elekie&a/c doctor
One connector each side of the rear glass. You may have to remove trims for access. Take care . These contacts are fragile. Not convinced this is your problem.
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Sat 24 Oct 2020 17:38
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - Trawlerman
One connector each side of the rear glass. You may have to remove trims for access. Take care . These contacts are fragile. Not convinced this is your problem.

Okay that’s a bit too sophisticated for me. I will just tape-over the demister button for the time being. Assuming the problem isn’t just the wrong style of fuse, which I will confirm tomorrow when my correct ones arrive. Thanks again for everyone’s help.
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Thu 29 Oct 2020 00:28
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - Trawlerman
Just an update on this.

I have realised that the fuse 36 also blows first thing in the morning, if the heating was already switched on. As if there is some kind of surge from the heating (control) that only happens if the engine is cold.

If I leave the heating switched off and let the engine warm up, then I can switch on the heating and the fuse doesn’t blow.

Any ideas please?
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Wed 4 Nov 2020 11:20
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - Trawlerman
Just an update on this. I have realised that the fuse 36 also blows first thing in the morning, if the heating was already switched on. As if there is some kind of surge from the heating (control) that only happens if the engine is cold. If I leave the heating switched off and let the engine warm up, then I can switch on the heating and the fuse doesn’t blow. Any ideas please?

So I heard there can be problems with the Civic heating if the temperature is below 10C. Today I tried leaving a cup of hot water on the floor under the steering wheel for 15 minutes or so. Sure enough the temperature displayed on the dashboard went up from 7 degrees to 12 degrees, and this allowed me to switch on the heating controls without fuse 36 blowing. What is it about 10C? Does the car try to do something drastic below that temperature, which causes a mini surge of some kind? Turning into a bit of a saga this...

Edited by Trawlerman on 04/11/2020 at 11:21

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Wed 4 Nov 2020 12:26
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - elekie&a/c doctor
Do you have heated windscreen washer jets ,? I can’t see them listed on the fuse plan , but if they are fitted , may be worth disconnecting them .
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Wed 4 Nov 2020 13:23
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - Brit_in_Germany

No idea about the Civic but some cars have an electrical auxiliary heater to pump warm air into the cabin before the engine gets up to temperature.

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Wed 4 Nov 2020 13:36
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - Trawlerman

No idea about the Civic but some cars have an electrical auxiliary heater to pump warm air into the cabin before the engine gets up to temperature.

Thanks, it seems the Civic does have one (they’re available on eBay) but am not sure how to disconnect it to test the theory. I am guessing it uses the control system via fuse 36. I can’t find a separate fuse for the auxiliary heater itself in the diagrams I’ve seen.

Edited by Trawlerman on 04/11/2020 at 13:37

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Wed 4 Nov 2020 13:24
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - Trawlerman
Do you have heated windscreen washer jets ,? I can’t see them listed on the fuse plan , but if they are fitted , may be worth disconnecting them .

Thanks I will take a look.
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Wed 4 Nov 2020 13:56
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - elekie&a/c doctor
Unlikely to have an auxiliary heater unless it’s got a Diesel engine .
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Wed 4 Nov 2020 14:12
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - Trawlerman
Unlikely to have an auxiliary heater unless it’s got a Diesel engine .

Sorry yes it is diesel, I should have said previously.
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Wed 4 Nov 2020 14:43
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - elekie&a/c doctor
In that case it will have a small auxiliary electric heating element that slides into the heater box. Not sure which side of the lower dash you need for access . Looks like a large plug connector with about 7 wires attached .
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Wed 4 Nov 2020 15:26
Honda Civic 2009 - Autoelectrics - controls circuit & damaged mirror - Trawlerman
In that case it will have a small auxiliary electric heating element that slides into the heater box. Not sure which side of the lower dash you need for access . Looks like a large plug connector with about 7 wires attached .

Thanks, apparently I need to remove the entire fascia. Think it would be less work for me just to use my cup of hot water every morning!
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