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.

[macadamianut]

Quick update,

New (probably crappy reman) alternator in place and fusible link replaced = blow ignition fuse over and over again when turning key to start.

Indicative of anything in particular? Short to ground somewhere?

Thanks

[oab_au]

Originally Posted by macadamianut

Quick update,

New (probably crappy reman) alternator in place and fusible link replaced = blow ignition fuse over and over again when turning key to start.

Indicative of anything in particular? Short to ground somewhere?

Thanks

It may be a slow process, of removing all the fuses, under the hood, then putting them in one by one, checking if the short is still there. That can tell which circuit the short is on.
Start with the slow-blow fuses in the un/hood box. The big square ones.
Do you have the WSM?

Harvey.

[macadamianut]

Harvey,
Does WSM mean service manual?

When cranking, fusible link gets hot and no start as it eventually blows the fuse.
I am wondering if the ECU is toasted dark.

Lights, wipers, climate, cruise switch and radio all working. Battery tests okay, voltage wise.
Doesn't the ignition fuse also do the restraint system. Is that why I had the random airbag light? Maybe a seperate issue.

Also new alt is a Bosch 95 amp. Tried to check codes but no light and I'm sure they were all erased.

Hope this helps narrow things.


Thanks

[oab_au]

Originally Posted by macadamianut

Harvey,
Does WSM mean service manual?
Yes will help if you do.

When cranking, fusible link gets hot and no start as it eventually blows the fuse.
Is it the link that blows or a fuse, what fuse No.?
I am wondering if the ECU is toasted dark.
Will see.

Lights, wipers, climate, cruise switch and radio all working. Battery tests okay, voltage wise.
Ok I will check thoes circuits
Doesn't the ignition fuse also do the restraint system. Is that why I had the random airbag light? Maybe a seperate issue.
Thoes units Air bag, Steering ect. come on because they are wired to the alt light. If thle car ran the battery low, these would not work.
Also new alt is a Bosch 95 amp. Tried to check codes but no light and I'm sure they were all erased.
Which unit did you check Ecu, Tcu ?
Does the power light come on?
Hope this helps narrow things.


Thanks

If you can answer these , it will help.

Harvey.

[macadamianut]

Harvey,

Thanks. Have not seen the power light.

Fuse that blows is the ignition fuse. Have not run tests on ECU yet. Will try that or try to find another ECU.

[oab_au]

Originally Posted by macadamianut

Harvey,

Thanks. Have not seen the power light.

Fuse that blows is the ignition fuse. Have not run tests on ECU yet. Will try that or try to find another ECU.

Yes that looks likely. Fuse16 feeds the ECU, but also the fuel pump relay, that would have been closed when the surge happened.
So If the fuel pump won't run, even with another ECU have a look at that.

Harvey.

[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.

[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...