93 dodge dynasty - engine cooling fan problem

Hello,

I recently acquired a 1993 dodge dynasty with 3.3L v6 from my uncle,
and the engine cooling fans do not run. He was trying to diagnose this
problem, but had not finished. All he knows is: The fans do work, as
they ran when he jumped them from the battery. He asked a friend who is
more knowlegable about cars about this problem, and this friend said
that the problem was most likely the engine coolant temperature sensor.

I have purchased the Chilton repair manual for this car, but the manual
also covers 12 or so other similar models, and so does not devote much
space to any one of them. The book outlines a procedure for testing the
entire cooling fan system, but is not very clear about the whole
process. In particular, the book has been very unhelpful in locating
specific components such as the aforementioned sensor, or the relay
between the fan and the computer (which the book lists as a possible
cause of this problem), or the "60-way connector" which it says is
something that connects to the computer and is a place to probe the
voltage of various wires.

I have no mechanical/electrical background whatsoever, and most of the
instructions in the book go right over my head. If it would just slow
down and stop assuming I know where all these components are and what
they do, I *think* I could work my way through the procedure
eventually, but as it is I am lost.

Also, the procedure does not seem to make any reference to a coolant
temperature sensor, which seems odd to me, especially as the similar
instructions for several of the other models specificially *do* mention
a temperature sensor of some kind. After all, wouldn't a bad sensor be
able to cause such a problem? If the computer never recieves the
information that the engine is getting too hot, it can't be faulted for
not turning on the fans, right? The procedure tests the fan motors
themselves, the "fan relay", the computer itself, and the wiring
between these components, but makes no mention of any sensors.

Basically, what I need is an explanation of how to find these
components, which of them is actually most likely to be the cause of
the problem, and how to actually go about removing/replacing them
(another thing the book does not help on). And it needs to be in
language a total car-repair illiterate can understand! <grin> I am a
financially strapped student, so I don't want to have to take this
thing to a mechanic. However, I'm no mechanic myself and darned if I
can figure all this out on my own.

Thanks in advance!

Brian,
If you go www.autozone.com
you will find that you can use their repair information for that
specific car. I was just there.
There are nice drawings showing where key parts are located, etc.
You may have to search a bit, but there is a lot of free info at this
site.

It could be the coolant sensor, it could be a loose connection or broken
wire, and it could be a bad relay.

If you can find the main electrical distribution and relay box (under
the hood near the battery on most models, but I'm not familiar with the
Dynasty personally), it should have a label inside it that indicates
which relays do what. You can do a quick-and-dirty test by swapping a
known-good relay (say the horn relay) with the fan relay and see if that
fixes the problem (and if the horn QUITS working...) to eliminate that
possibility.

What you REALLY need is a Chrysler factory service manual for the car,
not Chiltons or Haynes scrap paper. You can buy automotive literature
online- the real FSM is definitely worth the price, and is a lot closer
to the kind of step-by-step instruction you need, although it may still
assume some basic knowledge. But it doesn't leave out major steps the
way Chiltons and Haynes do.


Brian wrote:

> Hello,
>
> I recently acquired a 1993 dodge dynasty with 3.3L v6 from my uncle,
> and the engine cooling fans do not run. He was trying to diagnose this
> problem, but had not finished. All he knows is: The fans do work, as
> they ran when he jumped them from the battery. He asked a friend who is
> more knowlegable about cars about this problem, and this friend said
> that the problem was most likely the engine coolant temperature sensor.
>
> I have purchased the Chilton repair manual for this car, but the manual
> also covers 12 or so other similar models, and so does not devote much
> space to any one of them. The book outlines a procedure for testing the
> entire cooling fan system, but is not very clear about the whole
> process. In particular, the book has been very unhelpful in locating
> specific components such as the aforementioned sensor, or the relay
> between the fan and the computer (which the book lists as a possible
> cause of this problem), or the "60-way connector" which it says is
> something that connects to the computer and is a place to probe the
> voltage of various wires.
>
> I have no mechanical/electrical background whatsoever, and most of the
> instructions in the book go right over my head. If it would just slow
> down and stop assuming I know where all these components are and what
> they do, I *think* I could work my way through the procedure
> eventually, but as it is I am lost.
>
> Also, the procedure does not seem to make any reference to a coolant
> temperature sensor, which seems odd to me, especially as the similar
> instructions for several of the other models specificially *do* mention
> a temperature sensor of some kind. After all, wouldn't a bad sensor be
> able to cause such a problem? If the computer never recieves the
> information that the engine is getting too hot, it can't be faulted for
> not turning on the fans, right? The procedure tests the fan motors
> themselves, the "fan relay", the computer itself, and the wiring
> between these components, but makes no mention of any sensors.
>
> Basically, what I need is an explanation of how to find these
> components, which of them is actually most likely to be the cause of
> the problem, and how to actually go about removing/replacing them
> (another thing the book does not help on). And it needs to be in
> language a total car-repair illiterate can understand! <grin> I am a
> financially strapped student, so I don't want to have to take this
> thing to a mechanic. However, I'm no mechanic myself and darned if I
> can figure all this out on my own.
>
> Thanks in advance!
>