2003 G35 Coupe
Trying to find what fuse to look at that may be gone.
The light on the button to "engage" the rear window defroster does not come on when button pushed. Neither do I see the lines that show element is heating.
I talked with a dealer but they only look back to 2010 G37.

Your wiring diagrams are here starting on page GW-69:
https://www.nicoclub.com/service-manual ... 3%2Fgw.pdf

The fuses for the defogger are both underhood in the IPDM. You can find the layout for that here on PG-25:
https://www.nicoclub.com/service-manual ... 3%2Fpg.pdf

Those fuses are only for the window, the mirror defoggers have their own fuse in the cabin fusebox.

WOW! Sure don't want to make it easy to follow???

Where would be simplest chance to start looking?

Would I be right to check BCM Terminal 7 for power? That should prove all before it, correct?
Just have to find BCM terminal 7, lol.

Hey, electrons are your friends but chasing them around can be complicated. C'est la vie.

Pin 7 would bring down the whole BCM, not just the defogger. The car might not even start. Begin with those fuses in the IPDM, 77~78. Invest $4 in a bulb-type test lamp, when you test a fuse you're testing a power circuit. The right tool is a bulb that requires power, not a fancy multimeter or power probe. Put the alligator on ground and probe both sides of each fuse. There are four possible outcomes:
Neither side lights: Fuse has no power
One side lights: Fuse is blown
Both sides light: Fuse is good
Dim on both sides: Power supply to the fuse has resistance (bad wire or connector)
The Defogger Relay B417, if you need to go that far, is in the back of the car near the right taillight, See PG-52. The BCM is located underneath the cabin fuse block, see GW-62. Since the light isn't turning on, the pin you want to check first is 69 on the BCM. That's a signal line and not power, so break out your multimeter. Pin 69 should go from voltage to ground when you press the button, see GW-63. If it doesn't, check the other end of the wire, pin 11 on the A/C & Audio Control. If that goes to ground but pin 69 doesn't, you have a broken wire or bad connector. If it doesn't, your A/C & Audio Control has pooped the bed. Probably a dirty switch if so, so you may be able to disassemble and fix it.

Looking at the paperwork is pretty mind-boggling as to routing to turn on anything.

I have been having issues for about a year with regards my radio itself and can't say I have been "kind" to the unit.
Seeing as the circuit does say audio, could this be something related? It is just going into winter and so during summer no defrost needed.

It could be related if the radio issue is with the control panel and not the receiver. I haven't looked it up, but I'm pretty sure the receiver is a separate unit.

I found the defogger relay down by the spare tire "hole." With the key turned on, I can "feel" the relay clicking in. Looking at the schemeatic, it shows that fuse wire from 77 and78 go to this relay. With a lighted probe, it shows no "energy" to light the bulb. Number 1 of the relay does light the bulb.
Hoping it is not to difficult to access the two fuses I think I need to replace.

Yah, pin 1 on the relay is the coil, that has to have power if the relay clicks. If 3 and 6 don't have power then either the fuses are blown or you have a wiring issue. The IPDM on your ride is mounted vertically under a plastic cover next to the battery. See PG 26-28.

Bad information!

I read somewhere that to get access to these fuses that battery would have to be removed.

Lies! All lies.

I simply removed the holding pins of the two plastic parts "over" the battery and the cover to get at the fuses just slides right off.

Yes, both 20Amp fuses are trash.

Many many thanks for your assistance.

Now my next project is to get my radio to work all the time.

Urban Legend wrote: ↑

Thu Nov 24, 2022 9:52 am

Bad information!

I read somewhere that to get access to these fuses that battery would have to be removed.

Lies! All lies.

Lol, that's the internet for you. I don't know of anything Nissan where the IPDM is hard to get at. Awkward on a few, and you need to remove a screw or two on a few others. None of them require yanking the battery.

Anyway, glad you got it straightened away.