Wiring experts: plz help identify short circuit

[six50joe]

Order of events for our '97 Rav 4dr:
1. Had the same windshield leak problem covered here:
Leaking when it rains

At one point after a heavy rain, the wiring cluster on the lower left side of the dash was wet. When we noticed, we did not use the car until it dried out.
2. About a month later the dome light and cargo light stopped working, no fuses were blown.
3. A month after that, the stereo lost power. The fuse was blown, replacements blow immediately when key is turned on.
4. The open door light indicator stays on about 50% of the time when all doors are closed. When this occurs, keyless entry doesn't work.

5. Over the past weekend, I removed the dash board partially. just to the extent that it is shown here: http://www.autoclockrepair.com/yahoo...al.5751247.pdf

I had been hoping to see a relay I could get at that I could test, but couldn't see far enough to get at the wiring behind the dash, and I didn't want to completely remove it unless I knew the problem was likely there.

Instead, I focused on the wiring at the lower left side of the dash, since that was the part that was wet. The only relay I see there I think is for the ignition.

The ground there looked to be slightly corroded, so I disconnected it and cleaned the contacts up good before reconnecting.

Stuck at this point, and my mechanic will charge a fortune to work on this. Any ideas where the dome / stereo shorting problems might be?

Any help is desperately appreciated,
Joe

[Dr. Dyno]

My thoughts:
Water related issues usually go away once it dries. But long term leaks of many months can corrode relay contacts and circuit boards such as inside radios.

The door switch issue is directly related to the dome & interior lights. That's probably at the switch itself. I'd pull it out and check it. Best to replace it if there's ANY corrosion. Also make sure it's grounded solid if has to be.

For blowing fuse testing I replace the fuse with a 12V bulb. The short will light it brightly. Then start disconnecting items on that circuit until the test light goes out or dims.

Beyond the above I'd need a schematic. Then we could do systematic checks.

[six50joe]

Thanks DD,
I hadn't known of a 12V test bulb that fits into an automotive fuse socket; is this a common device you can find at a Radio Shack or an auto parts chain? I can see how that would help to narrow things down.

I was able to obtain from someone the wiring schematic for the dome light and radio, both attached here. In it, do you know what the dashed line (- - - - ) boxes represent, and what 'J/B' means? Also is a photo of the below-left dash area.

Every place I've been able to see so far: the lower left dash, the wiring inside the column from bottom left to top left of the windshield, and near where the dome light switch doesn't have any visible corrision; not to say there isn't any, but nothing I can see without disconnecting things. I haven't looked at any other areas yet because none had direct exposure to leaking water.

radio.JPG

dome.JPG

LowerLeftDashWiring.JPG

[Dr. Dyno]

The 12V test light is something I rig up myself by soldering wires to a bulb or a socket for one. Then Insert the wires into the fuse holder. Not that hard. Once while testing a high current draw circuit I used a headlight bulb!

A J/B is a junction box. Dashed lines are it's "borders." Each connector in your picture would be shown with dashed lines and a connector or J/B number.

The connectors pictured would probably work underwater. The pins are too far apart to short with water at 12V. Damage if there is any would be inside components where you can't see it.

Which fuse is blowing? Unless someone's pinched a wire you're likely to find a bad radio or relay.

[six50joe]

The perpetually blowing fuse is the one labeled either "RADIO" or "STEREO" on the inside of the fuse panel lower left of the steering wheel; it's the one on the bottom left.

I suspect that a pinched or stripped wire would be unlikely as there is nothing in recent memory that occurred that would cause that type of physical damage- but it's definitely not out of the question. I had just suspected water damage since the three problems started to occur (at different times) after the heaviest leak we had at the end of the summer.

That would leave (unless something else is being missed) a relay as you point out. But if that's the case, do you know how I could find out which one it is and where it's located?

[Dr. Dyno]

Originally Posted by six50joe

The perpetually blowing fuse is the one labeled either "RADIO" or "STEREO" on the inside of the fuse panel lower left of the steering wheel; it's the one on the bottom left.

You'd need to identify it on the schematic. The closest I see is at the top left of the second page. It's in the INSTRUMENT PANEL J/B ON LOWER LEFT SIDE OF DASH, but is labeled TURN & GAUGE FUSE, not RADIO. It's called HOT IN RUN OR START. The one you'll need to find will be HOT IN RUN since radios typically are not powered in START.

[six50joe]

Finding that J/B (and the relay in it that I'd need to test) is what seems to be the most difficult part so far; I think that if I could find the specific area to look in, more than half the battle would be won.

The turn signal flasher is in the cluster of connectors that's in the photo I took. The picture is actually sideways, but if it were upright the turn signal flasher would be at the top right. The top left is a relay that seems to be related to ignition. That particular group of connectors lower left of dash is the only easy one to get at because the panel that covers them comes off easily.

I'd rather avoid removing the entire dash unless it was highly likely that it's the only way to get to the relay or short. Does this sound like the only option?

Thanks again DD

[Dr. Dyno]

There is no point in finding any J/Bs or connectors UNTIL you determine on the schematics were the RADIO/STEREO fuse that's blowing is. You'll need to post that schematic. Then we can do a logical search w/o pulling lots of things apart which may be unrelated.

[Carbon]

Originally Posted by six50joe

The perpetually blowing fuse is the one labeled either "RADIO" or "STEREO" on the inside of the fuse panel lower left of the steering wheel; it's the one on the bottom left.

Are you sure?

I suggest you remove the radio. See if the fuse labeled either "RADIO" or "STEREO" blows then. If it doesn't blow, replace the radio.

'98 RAV4 Radio/CD Player has radio removal instructions.

[Dr. Dyno]

Originally Posted by Carbon

I suggest you remove the radio. See if the fuse labeled either "RADIO" or "STEREO" blows then. If it doesn't blow, replace the radio.

I suspect that's what he'll find too except that in the first schematic the ACC input to the radio is labeled CIG not RADIO. Is it just a bad cigarette lighter? Or something plugged into it? That's why I like the systematic approach. It's guaranteed to find the problem wherever it is.

And BTW Joe, which is it RADIO or STEREO?