[DeTomaso] Radiator Fans Running Constantly

MikeLDrew at aol.com MikeLDrew at aol.com
Thu Apr 10 00:13:52 EDT 2014


In a message dated 4/9/14 12 37 39, reillyms at live.com writes:


> I have the stock wiring and only disconnected the brown and black wires 
> from each of the temp sensors in the radiator during the removal and 
> installation (took photos to reinstall correctly).  I assume the temp senders are 
> fine as I believe if they failed the fan(s) would stop working. 
> 
>>>Normally correct, I think?   I wonder if, during the recoring process, 
they got damaged somehow so that they are always on?   It's easy to find out, 
even for an electric imbicile like me.   If I'm reading the diagrams 
correctly, the fan thermoswitches provide a ground to the fan relays.   When the 
radiator water heats up to a certain amount, the switches close, providing a 
ground path, which then causes the respective fan relay to close, and send 
power to the fan.

With the car cold, there should be no continuity between one side of the 
fan switch, and the other side.   Unplug the wires, get out your voltmeter, 
and check for continuity.   If it's there, there's your problem.

> >I plan to trouble shoot it all this weekend and any leads are 
> appreciated.  Also I saw some great ran and headlight control kits from 'Pantera 
> Electronics."  Anyone have experience with these?   They look to be a similar 
> solution to the headlight/fan control fix Mike Drew published previously.  
> 
>>>Jon's solution is much more sophisticated and elegant.   The article I 
co-wrote detailed how to take the heavy electrical loads off the headlight 
switch, and also how to provide a more 'pure' power and ground path for the 
fans, but they still operate in a conventional on-off fashion.   Jon's device 
is a variable fan motor system, which spins the fans at a variable speed 
depending on temperature conditions.   I don't find that to be necessary, but 
it is a complicated and intricate solution to what is otherwise a very simple 
problem.   Like everything he makes, I believe it's exquisitely engineered 
and constructed....

Mike
-------------- next part --------------
   In a message dated 4/9/14 12 37 39, reillyms at live.com writes:

     I have the stock wiring and only disconnected the brown and black
     wires from each of the temp sensors in the radiator during the
     removal and installation (took photos to reinstall correctly).  I
     assume the temp senders are fine as I believe if they failed the
     fan(s) would stop working.

   >>>Normally correct, I think?  I wonder if, during the recoring
   process, they got damaged somehow so that they are always on?  It's
   easy to find out, even for an electric imbicile like me.  If I'm
   reading the diagrams correctly, the fan thermoswitches provide a ground
   to the fan relays.  When the radiator water heats up to a certain
   amount, the switches close, providing a ground path, which then causes
   the respective fan relay to close, and send power to the fan.
   With the car cold, there should be no continuity between one side of
   the fan switch, and the other side.  Unplug the wires, get out your
   voltmeter, and check for continuity.  If it's there, there's your
   problem.

     >I plan to trouble shoot it all this weekend and any leads are
     appreciated.  Also I saw some great ran and headlight control kits
     from 'Pantera Electronics."  Anyone have experience with these?
     They look to be a similar solution to the headlight/fan control fix
     Mike Drew published previously.

   >>>Jon's solution is much more sophisticated and elegant.  The article
   I co-wrote detailed how to take the heavy electrical loads off the
   headlight switch, and also how to provide a more 'pure' power and
   ground path for the fans, but they still operate in a conventional
   on-off fashion.  Jon's device is a variable fan motor system, which
   spins the fans at a variable speed depending on temperature
   conditions.  I don't find that to be necessary, but it is a complicated
   and intricate solution to what is otherwise a very simple problem.
   Like everything he makes, I believe it's exquisitely engineered and
   constructed....
   Mike


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