Re: Total shutdown with elect power suging and fried fusible link
 

Fuse SBF-4, supplies fuse number 16, so that you need to only check items connected after fuse 16.

There is no need to disconnect battery for 10 minutes, as a simple direct short circuit is what you are looking for.

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Re: Total shutdown with elect power suging and fried fusible link
 

The book specifically states that " before trouble shooting on Airbag system, turn ignition switch "OFF" , disconnect battery ground cable and then wait at least 20 seconds "

I would follow the advice.:rolleyes:

Harvey.

Re: Total shutdown with elect power suging and fried fusible link
 

I actually had a manic alternator that had the regulator go bad after less than 60 days. Blew out my headlights and tail lights. My dash lit up like an Xmas tree and I figured my alternator belt had broken. Was surprised to see 18.5volts on multimeter. Manic will replace for free but my car is my daily driver and they did not even have cores in stock. I was told I needed to wait 2 weeks or more. So my $160 alternator became a $30 core at orielly.

Re: Total shutdown with elect power suging and fried fusible link
 

Harvey,

The short is happening when key is switched to ON or START position. Short is not occuring in the ACC position.

Will try to run some more checks today.

Thanks,

Re: Total shutdown with elect power suging and fried fusible link
 

Spent some time trying a few more thing to narrow things down.


1. Removed B4 harness connector. Still popped fuse 16 when key switched to ON position.

2. Removed steering column shroud and disconnected yellow airbag connector. Still popped fuse 16 when key switched to ON position.


---The only time fuse 16 won't blow in the key ON position is when SBF 4 is removed from the underhood panel.---

Other info:
1. Accessory lights function fine.

2.Voltage regulator wires are cooked. See Pic.

3. Ignition key cylinder is very loose on the security screws. Does it need to be seated tight to ground properly?


Is it worth disassembling the underhood fuse panel to see if connections for SBF 4 and fusible link are damaged?

Not sure what to do next.

Thanks,

Re: Total shutdown with elect power suging and fried fusible link
 

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Those regulator plug wires show signs of some serious arcing. Not sure if this has an external cause or from within the alternator.

http://www.subaru-svx.net/forum/atta...1&d=1363818901
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Re: Total shutdown with elect power suging and fried fusible link
 

Further thoughts on my last post

Does the fuse blow when the alternator connector is removed as shown? If it does,check the wire for a short circuit remaining somewhere along the wire or where it terminates.
Are they completely insulated from each other?

If the fuse does not blow with the plug removed the short shown must be within the alternator.

The ignition switch being loose could mean a short here because the wires could be tangled and shorting. If the alternator plug check proves nothing check the ignition switch.


NOTE: If you remove the lower panel under the steering wheel and the steering column covers you will be able to see the two security bolts. If they are loose, you cannot tighten them too much or the heads will shear off and make them difficult to remove. They are designed to do this

Pick up 2 replacement allen-head bolts, 8-1.25 metric, at the hardware store. They have about .75" grip length. The heads of the bolts won't quite fit down in the recessed hole on the ignition switch. You can grind off a little metal around the outside of the heads with the grinder. You can also leave the heads riding on top of the ignition switch housing. It works fine either way. They can then be tightened down securely.


Procedure for removing what you need to gain access to the ignition switch can be found in this thread HERE. Read the beginning of the thread, the actual procedure is in post 6.

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Re: Total shutdown with elect power suging and fried fusible link
 

As far as I can see, the SBF4 feeds fuse 16, that feeds;
The ECU, TCU, FUEL RELAY, MAIN RELAY, AIR BAG, IGNITION COILS. Also lights on the dashpanel. I can't see anything that uses that fuse.

As you have disconnected the Fuel relay, Main relay, replaced the TCU, ECU, Disconnected the Ignition coils (B4) and the Air Bag power (yellow B58), but it is still there.

The wiring to the Reg has been damaged, but I don't see it causing a problem.
The back of the loose Ign switch may cause a short, maybe?

As there could be a number of units that are shorted, it would be worth disconnecting all those units at the same time, to see if it is still there, to only leave melted wiring as a cause.

Harvey.

Re: Total shutdown with elect power suging and fried fusible link
 

Reading back over this thread, I see that only the ECU has been replaced, mentioned in post 22. There is no mention of having replaced the TCU. Has this been done?

Unplug the TCU and test for fuse 16 blowing with the TCU disconnected. Even if replaced, the replacement could be faulty as could the replacement ECU which should also be disconnected for testing. At this stage in the problem, nothing can be left to chance.

I'm still hoping that the problem lies in the ignition switch/ alternator.

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Re: Total shutdown with elect power suging and fried fusible link
 

Where is the emoticon for the "forehead slapper"? I didn't think to try with the fried volt reg plug unhooked. I guess this will do.... I am a :tard:

ECU and TCU were both replaced. Will try unhooking them all and also addressing the loose ignition cylinder.

I will also closely examine all wiring and grounds associated with alternator. They all seem pretty heat hardened.

Thanks for your continued support.

Re: Total shutdown with elect power suging and fried fusible link
 

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Something else occurred to me while looking at your photo of the plug. I looks to be a fairly new alternator.

Christian at Maniac Electric Motors has cautioned many times about overtightening the nut on the top of alternator that holds the power connection, usually on installation. Doing so puts stress on that stud, then they occasionally break and twist internally. Check that as well.

Since the stud has battery power and the case is grounded through the mounting bolts, any twisting internally would set off a short through inadvertant contact. Would be interested to see if that would be related to the fried wires on the plug. How are the wires on top of the alternator?

They are available for replacement cheaply. See my thread here with a link.

http://www.subaru-svx.net/forum/show...ost#post690551


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Re: Total shutdown with elect power suging and fried fusible link
 

Forget the Alternator, its not in the circuit. If there was a short at the alt. you would not have to turn the key on to get the short.
It would short as soon as you connected the battery terminal.

Harvey.

Re: Total shutdown with elect power suging and fried fusible link
 

The Alt is not the problem.
If you disconnect all of those units, that I listed and the short is still there, it means that they are not the problem. Leaving only the wiring.

If the short is not there with all of them disconnected, then plug them in one at a time testing for the short each time, to see which produces the short.

Harvey.

Re: Total shutdown with elect power suging and fried fusible link
 

At this stage every possibility must be checked and the damaged sensing wire provides factual evidence. The exact routing of the several white wires coming from the alternator has never been properly established. Under these circumstances, I believe that it is reasonable to suspect that the sensing wire could possibly be supplied via fuse 16. This being the case the short circuit could involve the alternator and in several different ways.

What is the condition of the wires coming from the alternator?

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Re: Total shutdown with elect power suging and fried fusible link
 

There are possibly 50 or so other bits of wiring and plugs that you could check, where do you want to start?

Of what? Only of having carried excess current, from the failed reg.

Don’t know about that, but the book shows wiring quite plainly, I can follow it. You and your advisor must have missed that part of your Alternator Thread.

Just look at the wiring in the book, it shows two connections to the plug on the side of the alternator, one white is straight from the battery. The other brown wire is the ground wire for the Generator warning light in the dash, fed from fuse No.15.

Harvey.