Diaries of a Subaru (ot)

[A.K. Boomer]

The problem; the patients battery was draining down overnight - for the most part not to where the car would not start but just start to crank slower - if the situation was to where the car had to sit for a few days then there was trouble...

A quick test of hooking up an amp meter between the battery's cable showed a constant draw of roughly .220 amps, or the equivalent of about half the draw from your average dome light... way too much.




Procedure; disconnect alternator and make sure diodes are not "backbleeding" --- no change.

plan B - start pulling fuses one at a time and placing them back - walla - "interior/clock" fuse takes the draw to zero,
close garage door and pull blinds on shop windows, open seat to trunk and make sure trunk light is not staying on, look into glovebox (without opening it) to make sure no light - even rule out ashtray and vanity visor lights, No go, conclusion; draw is most likely coming from circuitry devise ------- unplug alarm system, unplug many major connectors under dash, nothing

unplug factory sub-woofer underneath drivers seat (car had deluxe system)

draw goes from about .220 to .110 hmmm head straight to radio, unplug - draw goes to zero... WTF? ok ------------

tear into dash - me thinks .220 amps will show up in detectible heat the way a dome light will warm up your hand, get radio out and sure as hell the output cooler block on back of radio is slightly warm....

damn - im in deep - but why stop now, things are just getting interesting, tear into radio - remove CD player guts, then I see it;






Holy crap - some kind of highly conductive electrical fungus has taken over the board,
The thing is - is this is a very nice Kenwood and not all that old, call up the customer (awesome people) and tell them the scoop of what I found out and I hear kinda giggling over the phone about a slight accident the Misses had with a spilled drink in the cup holder (that resides right above the radio) and how it shut down the unit with a "high humidity" warning until it dried out,,, crazy... must have been corrosive coke or pepsi me's thinking...

esp. when you look at this pic;



To be continued...

[A.K. Boomer]

Ok --- so go price a new kenwood - not all that bad but problemo, the newer units have a different style and smaller number pin aux. input in back of unit and this is critical due to the fact that they have a special satellite hook-up for existing radio that will not fit new one, sooooo - they will have to spend more money and most likely at an install shop to get it all upgraded,

so alright, im going to try cleaning the old unit with baking soda and a toothbrush,,, get it all clean - let it sit in the sun half the day, put it all together and the draw is gone, excellent...





one big problem however - the unit will not power on, gave up for the rest of that day pretty frustrated,,,
woke up the next morning and started testing resistors in the immediate area of the clean-up, found two that where open, soldered in some exact copies from a spare junk unit I had laying around (they were about the size of a flea)
and the unit takes off and works fine now, people are happy and can't believe I took it as far as I did,

It seems the conductive fungus may have very well destroyed the resistors but it was also making them function due to bridging across them and therefor allowing enough current to function the brain chips...

[j king]

Impressive deduction work there Boomer

[WhatTheFlux!]

Nice bit of troubleshooting there! I would have never suspected the radio.

[A.K. Boomer]

Thank you kind Sir... uh ughm Sirs :-)

[bhowden]

I once had a Subaru DL that had a similar battery drain issue. Spent way too much time for what it turned out to be. Quickly tracked it to a fuse that powered several things. Turns out there is a small switch on top of the steering column that turns on an exterior light. I had owned the car for years and had never seen it. I also had a VW that used the tire pressure in the spare tire to power the windshield washer bottle. I over pressurized the spare tire and ended up bursting the hose that goes to the squirter. A month or so later the radio quit. Guess where the water + soap went.....

Brian

[skunkworks]

Is this a subaru where the cup holders are above the center console? we had one like that - pop/whatever would splash into everything below. vents didn't adjust /diverters didn't work, radio buttons would stick.. Poor design..

Edit - we still like subaru and have a 2010 forester now..

sam

[vpt]

An FYI

I have had 4 different drinks spilled into the laptop I am typing on right now. Nearly total flood out, puter shut down right away, funny smells and all. The quickest, easiest, best way I found to clean it out (after taking it apart) was brake cleaner and a tooth brush (for the sticky stuff). This laptop (labtop?) has been sprayed down at least 4 times with brake cleaner. And not nicely either, total brake cleaner dripping wet bath and blow gun in the shop.

After my kid threw my cell phone in the aquarium (found it an hour later) I used the same exact method for it and it is still working great to this day!

I am convinced it is the way to go for drying out and cleaning electronic boards and components.

[A.K. Boomer]

Andy, I pretty much inadvertently did the brake clean thing after the unit would not power on, I had sealed it with battery terminal sealer after cleaning, at first I thought that might be it so I took brake cleaner to the sealer to get it off to be able to inspect the resistors properly,

Now that were on the subject, question to the electronics guru's --- what do you spray on a board that's been eroded some to make sure it doesn't follow the same old paths?

what is the clear coat they put on boards and where can you buy it?

I called radio-shack and the gurl there told me to try google, nice

[nc5a]

Nicely done A K. Not many can troubleshoot worth a damn these days.

Ron

[batt-man]

give the board a good scrub with a suitable solvent (brake cleaner, ipa, etc) and a toothbrush, then just give it a light spray from a generic spray-bomb type lacquer can. If it's just for a small area on a pcb you can buy lacquer "pens" that work well although a bit pricey...

http://www.halfords.com/webapp/wcs/s...egoryId_165495

Cheers
Batt

[MrFluffy]

Andy, I pretty much inadvertently did the brake clean thing after the unit would not power on, I had sealed it with battery terminal sealer after cleaning, at first I thought that might be it so I took brake cleaner to the sealer to get it off to be able to inspect the resistors properly,

Now that were on the subject, question to the electronics guru's --- what do you spray on a board that's been eroded some to make sure it doesn't follow the same old paths?

what is the clear coat they put on boards and where can you buy it?

I called radio-shack and the gurl there told me to try google, nice

The coating that goes on pcb's is called conformal, but you need a conformal dissolvant to do any repairs (comes in a little can with a brush in the lid).
http://en.wikipedia.org/wiki/Conformal_coating

[gvasale]

I used to use a spray material made by CRC when doing printed circuit boards for Heald Machine (1974.) Forgot what the product # was. Used Trichlorothene to remove the stuff. Not sure if this info is helpful...

[A.K. Boomer]

I also had a VW that used the tire pressure in the spare tire to power the windshield washer bottle. I over pressurized the spare tire and ended up bursting the hose that goes to the squirter. A month or so later the radio quit. Guess where the water + soap went.....

Brian

I had forgotten all about that system, wow times have changed - lol

if memory serves correct there was some kind of fitting between the tire and the washer jug that only allowed the tire pressure to get down to a certain level and then it closed off so you still had a spare tire when you needed one, granted a low spare tire but better than a flat one....

[michigan doug]

Good diagnosis and repair!

My '63 vw had the spare tire/washer fluid system. It also had that cool mechanical fuel gauge. Float --> sealed lever --> cable --> gauge needle. It wasn't damped very well and the needle sloshed around a lot, as the gas sloshed around a lot. Your brain got good at real time averaging.

That stupid old car would get 39-42 mpg if I drove it nice.

Couldn't get out of its own way though. 42 whopping horsepower if I recall.

doug