Total shutdown with elect power suging and fried fusible link

[macadamianut]

Arrgggh.

Hi all,

She left me stranded today. Total power loss, then 3 short surges then dead.

Yesterday, the dash telltales said battery, brake, abs similar to the last time I had to replace my alternator and battery. Would illuminate at startup and would disapper after rpm climbed. Slight whining coming from alt pulley area. Also yesterday I would get an intermittent airbag light.

After cold startup this morning, car idled down to normal 600ish rpm when it got off the bypass air, but then would kick back up to high idle randomly. Defrosters, lights, radio was on/running at the time. Car ran normally for about 20 miles and then the show was over.

Fusible link terminals actually "fused" themselves to the fuseblock. Wire is broken, so hopefully the rest of the system is okay.

Surges were crazy, blower motor at max, all lights, stereo. the whole event lasted about 3 seconds. Then nothing. Had to work the shift interlock to get it on the tow truck.

What happened? Alternator blew? Positive terminal short? How does one remove the pins now welded into the fuse block? Do I get a new link and solder it to the now permanent pins to check fixes?

Any help is greatly appreciated.

Thanks

[oab_au]

Originally Posted by macadamianut

Arrgggh.

Hi all,

She left me stranded today. Total power loss, then 3 short surges then dead.

Yesterday, the dash telltales said battery, brake, abs similar to the last time I had to replace my alternator and battery. Would illuminate at startup and would disapper after rpm climbed. Slight whining coming from alt pulley area. Also yesterday I would get an intermittent airbag light.

After cold startup this morning, car idled down to normal 600ish rpm when it got off the bypass air, but then would kick back up to high idle randomly. Defrosters, lights, radio was on/running at the time. Car ran normally for about 20 miles and then the show was over.

Fusible link terminals actually "fused" themselves to the fuseblock. Wire is broken, so hopefully the rest of the system is okay.

Surges were crazy, blower motor at max, all lights, stereo. the whole event lasted about 3 seconds. Then nothing. Had to work the shift interlock to get it on the tow truck.

What happened? Alternator blew? Positive terminal short? How does one remove the pins now welded into the fuse block? Do I get a new link and solder it to the now permanent pins to check fixes?

Any help is greatly appreciated.

Thanks

Gee Mac you have some problems.

This one is the voltage regulator in the alt that has lost control of the voltage. All the lights that came on first were the first signs, as the voltage rose above 15V. When you started the engine in the morning the current changing the battery got high enough to blow the fusible link. Unfortunately The link only protects the battery, the rest of the electrical system is still connected. The alt keeps charging the rest of the electrical system to cause damage.

Depending on what was working at the time, and how high the voltage was, as to how much damage was done to the units, like ABS, ECU, TCU and all the relays that were on at the time.

Harvey.

[1986nate]

Originally Posted by oab_au

Gee Mac you have some problems.

This one is the voltage regulator in the alt that has lost control of the voltage. All the lights that came on first were the first signs, as the voltage rose above 15V. When you started the engine in the morning the current changing the battery got high enough to blow the fusible link. Unfortunately The link only protects the battery, the rest of the electrical system is still connected. The alt keeps charging the rest of the electrical system to cause damage.

Depending on what was working at the time, and how high the voltage was, as to how much damage was done to the units, like ABS, ECU, TCU and all the relays that were on at the time.

Harvey.

Sadly, these seem to be popping up a bit more often the couple years. Harvey, is it just a matter of the alternators and regulators nearing 20 years old or is there something more than that?

[oab_au]

Originally Posted by 1986nate

Sadly, these seem to be popping up a bit more often the couple years. Harvey, is it just a matter of the alternators and regulators nearing 20 years old or is there something more than that?

Well that, and the fact that the alt is mounted at the top of the engine shroded by the hood padding, that covers the vents to cool it, so when you turn the engine off, it gets a big heat soak into it, to cook the wiring and the reg.

Harvey.

[icingdeath88]

Is the regulator built into the alternator?

[Blacky]

Originally Posted by icingdeath88

Is the regulator built into the alternator?

Yes it is.

[oab_au]

John, I think this needs its own thread. Macs problem has not been resolved yet.

Harvey.

[macadamianut]

Harvey,

As per your previous suggestions:

1. Tried unhooking the fuel pump relay (both relays, not sure which is the fuel pump) under the dash attached to the steering column which still popped fuse 16 when ignition switched to ON position. So no joy there.

2. All fuses out of underhood box. Replaced one at a time until interior ignition fuse #16 popped.

It appears that SBF #4 slow blow fuse #4 is the circuit the fault is on. The SBF's themselves are not blown.

Also to mention that the car will crank even though fuse 16 is blown. All accessories still work. Wipers, climate, radio, windows, hazards, etc.

The quick connect to the alt voltage regulator has two wires that both look like they had gotten pretty hot.

Hope this info helps to narrow things down.

Thanks,

[WYOSVX]

Originally Posted by 1986nate

Sadly, these seem to be popping up a bit more often the couple years. Harvey, is it just a matter of the alternators and regulators nearing 20 years old or is there something more than that?

If this is happening more and more, it begs the question: what's a good prevention?

(I don't want to hijack, so maybe a post in "how to"?)

[1986nate]

Originally Posted by WYOSVX

If this is happening more and more, it begs the question: what's a good prevention?

(I don't want to hijack, so maybe a post in "how to"?)

Replace your alternator....
the regulator is internal and is what causes this. So there is no prevention.

[oab_au]

Originally Posted by 1986nate

Replace your alternator....
the regulator is internal and is what causes this. So there is no prevention.

We can't prevent the regulator from failing. , but we can prevent it from destroying a lot of electrical components in the process.

If you look in this thread, at post 15, it shows how to reconnect the alternator wiring to prevent this trouble. Post 27 explains why it happens.
http://www.subaru-svx.net/forum/showthread.php?t=49727

It is not a difficult job to do, but good insurance.


Harvey.

[icingdeath88]

Originally Posted by WYOSVX

If this is happening more and more, it begs the question: what's a good prevention?

(I don't want to hijack, so maybe a post in "how to"?)

That was the exact motivation behind my question about the regulator above. Contemplating picking up a maniac alternator for the built engine. But they are a wee bit pricey...

[jman050]

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.