Why you should remove the negative battery terminal before doing ANYTHING!!!!

I was lokking thorugh the Subaru manual to find out where the thermostat
was. I'm used to it being on TOP of the engine.

While it ididn't show the location, it did say, "Remove negative battery
terminal, and remove thermostat housing..."

Huh? Remove the - terminal berfore removing the thermostat housing?! WTF?!?!

Last night I went to pick up my papers for my "paper route" and saw a
big-ass GMC pickup I hadn't seen before. Then I saw one of my firend's
fathers, who started doing the papers about 10 days after I did. He
usually drive an '01 Pathfinder.

"Where's the Pathfinder?" "I wrecked it." "WHAT?!?!?!?!"

Well, he didn't really wreck it. He had a bad bulb in the overhead light.
He removed the lens, and the bulb was in pieces, but still working
intermittantly. He removed the bulb and replaced the lens, and then tried
to start the truck. No Go. The starter spins, but the engine doesn't catch.

Looks like he fried the ECU!!!! All the other lights work, the dome light
works, but the fuel pumpo doesn't energize. He tried the reset procedure
and nothing.

I had heard of this before; I can't remember what the car was, but someone
shorted out the ECU replacing the dome light...

Hachiroku ãƒ�ãƒ�ãƒ*ク wrote:
> I was lokking thorugh the Subaru manual to find out where the thermostat
> was. I'm used to it being on TOP of the engine.
>
> While it ididn't show the location, it did say, "Remove negative battery
> terminal, and remove thermostat housing..."
>
> Huh? Remove the - terminal berfore removing the thermostat housing?! WTF?!?!
>
> Last night I went to pick up my papers for my "paper route" and saw a
> big-ass GMC pickup I hadn't seen before. Then I saw one of my firend's
> fathers, who started doing the papers about 10 days after I did. He
> usually drive an '01 Pathfinder.
>
> "Where's the Pathfinder?" "I wrecked it." "WHAT?!?!?!?!"
>
> Well, he didn't really wreck it. He had a bad bulb in the overhead light.
> He removed the lens, and the bulb was in pieces, but still working
> intermittantly. He removed the bulb and replaced the lens, and then tried
> to start the truck. No Go. The starter spins, but the engine doesn't catch.
>
> Looks like he fried the ECU!!!! All the other lights work, the dome light
> works, but the fuel pumpo doesn't energize. He tried the reset procedure
> and nothing.
>
> I had heard of this before; I can't remember what the car was, but someone
> shorted out the ECU replacing the dome light...
>
>

Typical dome light bulb is a dual contact base, he may have caused a
momentary short circuit to ground removing the broken bulb. Sounds
far-fetched, but possible that that could have damaged something.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

Hachiroku wrote:
<snip crap>
> I had heard of this before; I can't remember what the car was, but someone
> shorted out the ECU replacing the dome light...

no way - the ecu's not even connected to the dome light. and they're
electrically protected against all kinds of "user error", including
battery reversal, over-voltage, dead shorts and static. short of direct
lightning strike, water damage, or fire, none of which have a single
damned thing to do with dome lights, the ecu's not going anywhere and
it's /certainly/ not going to be fubared by a bulb change.

jim beam wrote:

> Hachiroku wrote:
> <snip crap>
>
>> I had heard of this before; I can't remember what the car was, but
>> someone
>> shorted out the ECU replacing the dome light...
>
>
> no way - the ecu's not even connected to the dome light. and they're
> electrically protected against all kinds of "user error", including
> battery reversal, over-voltage, dead shorts and static. short of direct
> lightning strike, water damage, or fire, none of which have a single
> damned thing to do with dome lights, the ecu's not going anywhere and
> it's /certainly/ not going to be fubared by a bulb change.
Hi,
No way? If short caused a surge in the electrical system, anything is
possible. In cases like this mostly nothing serious happens but result
unpredictable. Protection is not absolute 100%.

"Tony Hwang" > wrote in message
news:6DtZi.198872$th2.150458@pd7urf3no...
> jim beam wrote:
>
>> Hachiroku wrote:
>> <snip crap>
>>
>>> I had heard of this before; I can't remember what the car was, but
>>> someone
>>> shorted out the ECU replacing the dome light...
>>
>>
>> no way - the ecu's not even connected to the dome light. and they're
>> electrically protected against all kinds of "user error", including
>> battery reversal, over-voltage, dead shorts and static. short of direct
>> lightning strike, water damage, or fire, none of which have a single
>> damned thing to do with dome lights, the ecu's not going anywhere and
>> it's /certainly/ not going to be fubared by a bulb change.
> Hi,
> No way? If short caused a surge in the electrical system, anything is
> possible. In cases like this mostly nothing serious happens but result
> unpredictable. Protection is not absolute 100%.


Bull****!!

Mike wrote:
> "Tony Hwang" > wrote in message
> news:6DtZi.198872$th2.150458@pd7urf3no...
>
>>jim beam wrote:
>>
>>
>>>Hachiroku wrote:
>>><snip crap>
>>>
>>>>I had heard of this before; I can't remember what the car was, but
>>>>someone
>>>>shorted out the ECU replacing the dome light...
>>>
>>>
>>>no way - the ecu's not even connected to the dome light. and they're
>>>electrically protected against all kinds of "user error", including
>>>battery reversal, over-voltage, dead shorts and static. short of direct
>>>lightning strike, water damage, or fire, none of which have a single
>>>damned thing to do with dome lights, the ecu's not going anywhere and
>>>it's /certainly/ not going to be fubared by a bulb change.
>>
>>Hi,
>>No way? If short caused a surge in the electrical system, anything is
>>possible. In cases like this mostly nothing serious happens but result
>>unpredictable. Protection is not absolute 100%.
>
>
>
> Bull****!!
>
>
Hmmm,
Live little longer and gain some more experience!

Tony Hwang wrote:
> jim beam wrote:
>
>> Hachiroku wrote:
>> <snip crap>
>>
>>> I had heard of this before; I can't remember what the car was, but
>>> someone
>>> shorted out the ECU replacing the dome light...
>>
>>
>> no way - the ecu's not even connected to the dome light. and they're
>> electrically protected against all kinds of "user error", including
>> battery reversal, over-voltage, dead shorts and static. short of
>> direct lightning strike, water damage, or fire, none of which have a
>> single damned thing to do with dome lights, the ecu's not going
>> anywhere and it's /certainly/ not going to be fubared by a bulb change.
> Hi,
> No way? If short caused a surge in the electrical system,

short won't cause voltage surge. measure the voltage across a battery
as you increase current load - voltage goes down, not up. only other
potential source of surge is back emf from relays, motors, etc, and
they're all diode/condenser protected, as is the ecu. bottom line: it's
not the dome light.


> anything is
> possible.

yeah, it could have been hit by meteorite.

> In cases like this mostly nothing serious happens but result
> unpredictable. Protection is not absolute 100%.

yeah, it could have been hit by meteorite.

jim beam wrote:
> Tony Hwang wrote:
>
>> jim beam wrote:
>>
>>> Hachiroku wrote:
>>> <snip crap>
>>>
>>>> I had heard of this before; I can't remember what the car was, but
>>>> someone
>>>> shorted out the ECU replacing the dome light...
>>>
>>>
>>>
>>> no way - the ecu's not even connected to the dome light. and they're
>>> electrically protected against all kinds of "user error", including
>>> battery reversal, over-voltage, dead shorts and static. short of
>>> direct lightning strike, water damage, or fire, none of which have a
>>> single damned thing to do with dome lights, the ecu's not going
>>> anywhere and it's /certainly/ not going to be fubared by a bulb change.
>>
>> Hi,
>> No way? If short caused a surge in the electrical system,
>
>
> short won't cause voltage surge. measure the voltage across a battery
> as you increase current load - voltage goes down, not up. only other
> potential source of surge is back emf from relays, motors, etc, and
> they're all diode/condenser protected, as is the ecu. bottom line: it's
> not the dome light.
>
>
>> anything is possible.
>
>
> yeah, it could have been hit by meteorite.
>
>> In cases like this mostly nothing serious happens but result
>> unpredictable. Protection is not absolute 100%.
>
>
> yeah, it could have been hit by meteorite.
hmmm,
Whatever you think. A car battery has lots of energy in it.
Think current in this case.

Tony Hwang wrote:
> jim beam wrote:
>> Tony Hwang wrote:
>>
>>> jim beam wrote:
>>>
>>>> Hachiroku wrote:
>>>> <snip crap>
>>>>
>>>>> I had heard of this before; I can't remember what the car was, but
>>>>> someone
>>>>> shorted out the ECU replacing the dome light...
>>>>
>>>>
>>>>
>>>> no way - the ecu's not even connected to the dome light. and
>>>> they're electrically protected against all kinds of "user error",
>>>> including battery reversal, over-voltage, dead shorts and static.
>>>> short of direct lightning strike, water damage, or fire, none of
>>>> which have a single damned thing to do with dome lights, the ecu's
>>>> not going anywhere and it's /certainly/ not going to be fubared by a
>>>> bulb change.
>>>
>>> Hi,
>>> No way? If short caused a surge in the electrical system,
>>
>>
>> short won't cause voltage surge. measure the voltage across a battery
>> as you increase current load - voltage goes down, not up. only other
>> potential source of surge is back emf from relays, motors, etc, and
>> they're all diode/condenser protected, as is the ecu. bottom line:
>> it's not the dome light.
>>
>>
>>> anything is possible.
>>
>>
>> yeah, it could have been hit by meteorite.
>>
>>> In cases like this mostly nothing serious happens but result
>>> unpredictable. Protection is not absolute 100%.
>>
>>
>> yeah, it could have been hit by meteorite.
> hmmm,
> Whatever you think. A car battery has lots of energy in it.
> Think current in this case.

do what i said - measure voltage as a function of load. then report
your results.

jim beam wrote:
> Tony Hwang wrote:
>
>> jim beam wrote:
>>
>>> Tony Hwang wrote:
>>>
>>>> jim beam wrote:
>>>>
>>>>> Hachiroku wrote:
>>>>> <snip crap>
>>>>>
>>>>>> I had heard of this before; I can't remember what the car was, but
>>>>>> someone
>>>>>> shorted out the ECU replacing the dome light...
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> no way - the ecu's not even connected to the dome light. and
>>>>> they're electrically protected against all kinds of "user error",
>>>>> including battery reversal, over-voltage, dead shorts and static.
>>>>> short of direct lightning strike, water damage, or fire, none of
>>>>> which have a single damned thing to do with dome lights, the ecu's
>>>>> not going anywhere and it's /certainly/ not going to be fubared by
>>>>> a bulb change.
>>>>
>>>>
>>>> Hi,
>>>> No way? If short caused a surge in the electrical system,
>>>
>>>
>>>
>>> short won't cause voltage surge. measure the voltage across a
>>> battery as you increase current load - voltage goes down, not up.
>>> only other potential source of surge is back emf from relays, motors,
>>> etc, and they're all diode/condenser protected, as is the ecu.
>>> bottom line: it's not the dome light.
>>>
>>>
>>>> anything is possible.
>>>
>>>
>>>
>>> yeah, it could have been hit by meteorite.
>>>
>>>> In cases like this mostly nothing serious happens but result
>>>> unpredictable. Protection is not absolute 100%.
>>>
>>>
>>>
>>> yeah, it could have been hit by meteorite.
>>
>> hmmm,
>> Whatever you think. A car battery has lots of energy in it.
>> Think current in this case.
>
>
> do what i said - measure voltage as a function of load. then report
> your results.
Hmmm,
No, current as a function of load! Do you remember the days of
generators under the automobile hoods?