Rev. light, blinkers, A/C, moonroof, PW all out, fuse blew again fast when in gear...
'04 Honda Accord EX, AT, 4 cyl. 90K. Been great except for pass door lock actuator (been out 2+ yrs)...

Hi all, new here. Very active member of other moto forum.

Other day, powered up car at night and noticed gauges out. Then more. Car locks AT in park, have to bypass it by pressing down shifter release under that pop out tab on Trans.
PW won't work at all, P Moonroof out too. Reverse lights out, don't come on. No blinkers, although the Hazard button will activate them all just not on the stalk. A/C not working either - no cold air and was working before. (no odometer, no gas gauge, no speedo, and we're still driving it daily).

Checked and fuse #21 blown "IG Meter" 7.5 amp. Borrowed "IG Wiper" 7.5 amp and got everything working immediately with new fuse car off, started car, still good, and either right after I hit the brakes or maybe 30 feet up the road gauges black out, blown same fuse, all same still not working again.

Checked around trunk for any wiring being severed (no electric work done on car, nothing added recently - car is completely stock). Pulled brake light bulbs. Passenger side brake light bulb not working. Swapped driver side brake bulb to pass side brake and then it worked, although it seemed to heat up pretty fast in my hand compared to working driver side... and it went from clear and darkened in a matter of minutes...
But brake lights (besides blown pass bulb) have always been working, radio fine, heated seats, climate control and fans, interior lights, headlights, P mirrors, P Seat, all work fine.

Any suggestions? I have a solid DVM but I don't have any real experience in tracing and fixing shorts. Also have 6-24 Volt bulb testors etc etc...

 

So hooked up a little test light with leads into my #21 empty fuse slot.
Went through whole circuit, the test light connects the circuit but won't blow (like a fuse will) and enables to pinpoint where the problem is.

Here's how this works,
Connected test light (which happens to be one rated for 6V - 24V) glows dim if there is not a problem or something that will blow normal fuse (short drawing too much juice).
BUT light will glow very bright when you've detected the bad area. (You can also rig this up with, say, a headlight bulb, tail light bulb etc... but be very careful to not connect two extension leads together when inserting them into either side of fuse block).

So in this case:
Wipers - working - normal dim glow
all 4 Power windows - working - normal dim glow
Power moon roof - working - normal dim glow
blinkers both - working - normal dim glow
reverse - working - normal dim glow

WHEN car (AT) is in 'Park' and I hit the brake pedal to shift - HA - light glows very bright and hear a little click!
When I shift into gear, and even reverse, neutral, D etc... I can hit the brake and it's fine, it's very specifically when car is in 'Park' and I hit the brake I am exposing the short in the system.

I read somewhere else that Honda's brake pedal switch aka brake light switch is somewhat notorious for going out.
Just bought replacement one for $10 at local O'Reilly's and will post later with results.

 

Hmm. Brake pedal switch I don't think is it. Tried new one and old one same results.
With test light in to complete circuit I can get everything on the car to work except I cannot shift out of park without manually pressing in override next to shift handle.
Perhaps the circuit being one way or other with brake switch made the light glow get brighter and didn't indicate the short was there.

But maybe for awhile before this all happened?? I have pass side brake light out although bulb looks fine it won't work in socket. And I have both reverse lights bulbs with broken filaments which I don't know if its related or a crazy coincidence.
Anyone?

 

Remove the reverse light bulbs and test again.

 

Ok, I did remove the reverse light last night. I will try re-testing it again now.
Thank you for the response Poorman!!

(could blown reverse lamps cause that fuse to blow and all this?? Is this a sort of 'safety' built in mechanism to tell the dumb driver both reverse or say all 3 brake lights are out, and by golly, the car is going to get the dumb driver's attention!?)

 

There is a fuse #7 for back up lights according to manual and fuse box cover. that fuse is not blown. I think it's a coincidence but will keep trying.

 

i just posted a six minute response to all this, very detailed and this p.o.s. site just timed me out with it's 'token' and wiped out my whole text. thanks for the constant ads too, those are really helpful.

 

The car blows fuse #21 any time for a split second AT goes into or through Reverse.
AT shift lock solenoid is working, I can hear it click loudly at AT console cover when I have a new fuse in #21 and haven't done anything involving reverse yet. It will also let me shift out of park with brake on like it's supposed to but if I go as far as Reverse BAM! fuse instantly gone. (like ACC key position or running in neutral or and other gear or park I have everything working and can shift gears etc..). I can hit brakes in any gear, no problem. Brake light always work and replaced brake switch and original wasn't faulty.

I traced two solid green with painted on grey spots as both the + 12V to both reverse light bulbs with black grounds. The greens I traced to upped shoulder rear passenger side connectors when I took out the leather side trim seatback bolster. I disconnected the connector there, and still blow #21. I had also put in new reverse bulb to test with same problem before I disconnected. So I know it's not bulb related in rear, nor is it have anything to do with final wiring from connector on into trunk and fixtures. I traced the larger wire loom down through both door sill covers, no obvious breaks or tears in loom or anything shorting outside of plastic to body.
I have a lot of the driver footwell plastics out when I did the brake switch and see there are TONS of green and grey painted dot wires in there to a dozen plus connectors. Nice. Anyone have an idea which to disconnect for testing etc...?
I have Digi Voltmeter and test alligator auto bulb things so where should I look now???

 

The wire color protected by the 7.5 amp fuse #21 is yellow.

It powers a bunch of different items that you listed previously.

The gauge control module is one of those items that is powered by the yel wire. There is a self-diagnostic test that you can try.

Push and hold trip/reset button
turn headlights on
Turn ignition switch on
Within 5 seconds, turn headlights OFF, then ON, then OFF.
Within 5 seconds, release the trip/reset button, then push/releas the trip/reset button 3 times repeatedly.

The car will test several items and you will hear beeps, etc.

What you will pay attention to is the mileage. If it says 88888888, then no problems were found. If a problem is found, it will read Error 1, Error 2,...

I know it sounds like a strange diagnostic, but I have tried this on my TSX and it works.

Let us know what you find.

 

Sounds like OBDII stuff... had my fun with that on junk Supra...
Will try that,

also wondering where the grounds are for this circuit, and if there's a wiring diagram available to see anywhere

Thinking it could be trans reverse switch on the actual transmission or the wiring from it, did a fast visual look tonight and think I spotted it and no visual tears etc... but in daylight will probably pull that connector and see what that does as well.

Other things it could be?