'95 Bonneville - Cooling Fans Stay on

3.8
Okay when started from cold.
Except this morning when he used his remote start he noticed both fans
wound up then shut off when he started. Might always happen but he
noticed it today.
Once operating temp is reached both fans come on and stay on until
engine is shut down. If restarted before engine has fully cooled
down, fans come on upon restart.
Car is running fine, and at normal operating temp.
Started a couple weeks ago.
Suggestions?

TIA,

--Vic

On Sat, 23 May 2009 20:26:07 -0500, Vic Smith wrote:

> 3.8
> Okay when started from cold.
> Except this morning when he used his remote start he noticed both fans
> wound up then shut off when he started. Might always happen but he
> noticed it today.
> Once operating temp is reached both fans come on and stay on until
> engine is shut down. If restarted before engine has fully cooled
> down, fans come on upon restart.
> Car is running fine, and at normal operating temp.
> Started a couple weeks ago.
> Suggestions?
>
> TIA,
>
> --Vic

Check the temp sensor for the fans. AFAIK, Nissan used a type that, if it
goes bad, closes and grounds the fans, causing them to run continuously.
This is because it's better to have the fans running when you don't need
them, than not running when you do!

Vic Smith wrote: (95 Bonneville Cooling Fans Stay On)

3.8 Okay when started from cold. Except this morning
when he used his remote start he noticed both fans wound
up then shut off when he started. Might always happen
but he noticed it today. Once operating temp is reached
both fans come on and stay on until engine is shut down.
If restarted before engine has fully cooled down, fans come
on upon restart. Car is running fine, and at normal operating
temp. Started a couple weeks ago. Suggestions?
__________________________________________________ ________________

Hachiroku wrote:

Check the temp sensor for the fans. AFAIK, Nissan used a
type that, if it goes bad, closes and grounds the fans,
causing them to run continuously. This is because it's
better to have the fans running when you don't need
them, than not running when you do!
__________________________________________________ __________________

In some cars the second fan engages when the AC is turned
on, then if the AC control was left in the AC or the Defrost
position, the second fan would come on at startup.

Rodan.

On May 23, 9:26*pm, Vic Smith > wrote:
> 3.8
> Okay when started from cold.
> Except this morning when he used his remote start he noticed both fans
> wound up then shut off when he started. *Might always happen but he
> noticed it today.
> Once operating temp is reached both fans come on and stay on until
> engine is shut down. *If restarted before engine has fully cooled
> down, fans come on upon restart.
> Car is running fine, and at normal operating temp.
> Started a couple weeks ago.
> Suggestions?
>
> TIA,
>
> --Vic

When the coolant temp sensor gets corrosion on the tip from being
submerged in the anti-freeze it can throw off the readings making your
engine think it needs to be on. You can try to remove the sensor and
clean the tip, or just go get a new one.

also double check your coolant level.

On Sun, 24 May 2009 03:29:33 -0700 (PDT), m6onz5a
> wrote:

>On May 23, 9:26Â*pm, Vic Smith > wrote:
>> 3.8
>> Okay when started from cold.
>> Except this morning when he used his remote start he noticed both fans
>> wound up then shut off when he started. Â*Might always happen but he
>> noticed it today.
>> Once operating temp is reached both fans come on and stay on until
>> engine is shut down. Â*If restarted before engine has fully cooled
>> down, fans come on upon restart.
>> Car is running fine, and at normal operating temp.
>> Started a couple weeks ago.
>> Suggestions?
>>
>> TIA,
>>
>> --Vic
>
>When the coolant temp sensor gets corrosion on the tip from being
>submerged in the anti-freeze it can throw off the readings making your
>engine think it needs to be on. You can try to remove the sensor and
>clean the tip, or just go get a new one.
>
>also double check your coolant level.

Thanks all for the tips.
Also found other possibilities - relays, shorts, etc.
Will post the fix when he does it.

--Vic

On Sun, 24 May 2009 16:51:24 -0500, Vic Smith
> wrote:

>On Sun, 24 May 2009 03:29:33 -0700 (PDT), m6onz5a
> wrote:
>
>>On May 23, 9:26Â*pm, Vic Smith > wrote:
>>> 3.8
>>> Okay when started from cold.
>>> Except this morning when he used his remote start he noticed both fans
>>> wound up then shut off when he started. Â*Might always happen but he
>>> noticed it today.
>>> Once operating temp is reached both fans come on and stay on until
>>> engine is shut down. Â*If restarted before engine has fully cooled
>>> down, fans come on upon restart.
>>> Car is running fine, and at normal operating temp.
>>> Started a couple weeks ago.
>>> Suggestions?
>>>
>>> TIA,
>>>
>>> --Vic
>>
>>When the coolant temp sensor gets corrosion on the tip from being
>>submerged in the anti-freeze it can throw off the readings making your
>>engine think it needs to be on. You can try to remove the sensor and
>>clean the tip, or just go get a new one.
>>
>>also double check your coolant level.
>
>Thanks all for the tips.
>Also found other possibilities - relays, shorts, etc.
>Will post the fix when he does it.
>

Read on the Bonneville forum where a guy with the same problem
did a lot of stuff, swapping PCM's, testing relays, disconnecting,
reconnecting battery, scanning, etc, etc.
Thread lasted 9 days!
The ninth day he traced the wires from the A/C high pressure switch
and found one out of the harness and the belt had cut it.
His fault from previous work. Fixing the wire fixed the problem.
Happened to me once when I did a valve cover gasket and didn't rehang
a harness. Worse though, because the primary ignition wire had
fallen behind the head and a bit of the insulation had melted.
When the head was hot apparently the current flow was reduced enough
that the shorting would stall the engine.
And the slightest bump could move the wire and short it. Or not.
This was that sweet 6 that came with a '74 Dart.
Good engine.
Never had a problem until the engine was fully hot and I hit a bump
right. It would usually restart after a few minutes.
Lasted a couple months and cost me a number of highway engine kills,
one tow back home that canceled an Easter family outing, an
unnecessary control module, and a lot of grief checking fuel pressure
, and everything else I could.
It always ran fine when not on the road.
I was leaning over the engine after doing a fuel flow test, which came
out good. Depressed as hell because my next step was to drop the gas
tank and see if there was something in there that could block the
strainer. Man, I was sick of that thing defeating me.
Then I got lucky. The sun was at the exact angle to shine light on
the back of the head, through the hood crack at the hinge end.
I saw a glint of copper. Half an inch of electrical tape fixed it.
And I've always been real careful to rehang wires since then.
ALWAYS PROPERLY REHANG WIRES AND HARNESSES.
But I digress.........
My kid was over yesterday with his Bonneville and I told him maybe it
was a relay, maybe the PCM, maybe the coolant temp sensor, etc, but
the one guy who actually had the problem and fixed it had a cut A/C
switch wire.
He went outside and was back in 5 minutes.
His wires are fine, but when he tapped the A/C switch the fans cut
off. And when he tapped again, the fans went back on, and so on.
So he'll put a new switch in.
Ain't the internet simply wonderful?

--Vic