Need help with my car (90 Mercury Sable)---fan problem

[Ed_S]

Dave, what relay did you replace? The fan relays are in a control module located above the radiator, under a plastic shield.
It'll be marked xxxx-12B577-xx

Not being at a catalog, I'm not sure of that year, but SOME Taurus / Sable's also have a ballast resistor in the fan circuit. Large white ceramic block above the trans. (roughly)

Does the fan run with either the AC or defrost on?
If so, then the low-speed relay's gone - part of the module I described.

And that's about as far as I can go in diagnostics - remember, I'm a partsman, not a tech!

[Gomer]

For another good source of auto answers... check out the automobile forums at www.doityourself.com very very helpful there.

[daveleau]

Quote:

Originally posted by larrwhit
just wire the fan so it comes on with the ignition switch (like the radio for example) and let it run all the time

Hmm, good idea. I never thought of that. I'd have to think about how I'd set it up... I'll leave this as a last resort.

I have a Chiltons and will check te wiring diagrams out. I have a temperature switch which I cannot find referenced in the Chiltons. I need to find it so I can replace it (I have the part already).

The relay that I replaced was the main relay under the radiator/fan shield and on top of the radiator. Darn thing cost $90 and I can't take it back.

I will check to see if the fan comes on when I have the defroster on.

Thanks for the help guys. I will check that link out as well.
Dave

[Cyclone2]

Ummm Psst...Dave- keep the Miata

[glohworm]

Dave,

larrwhit did it again! This guy's going to be a real good contributor here. I like your idea too. Just wire an on/off switch for the fan. Works for me!

[daveleau]

Quote:

Originally posted by Cyclone2
Ummm Psst...Dave- keep the Miata

lol! I wish we could!

[vfrxsw]

Quote:

Originally posted by Ed_S
Not being at a catalog, I'm not sure of that year, but SOME Taurus / Sable's also have a ballast resistor in the fan circuit. Large white ceramic block above the trans. (roughly)

Does the fan run with either the AC or defrost on?
If so, then the low-speed relay's gone - part of the module I described.

And that's about as far as I can go in diagnostics - remember, I'm a partsman, not a tech!

I was also trying to remember what year they had the resistor on the cooling fan but my memory fails me and the cd's of the manuals I have only go back to 1992. If the fan does work when powered directly and does not go on by temp or when a/c is on this resistor would be the most likely problem if it has one. It is a white ceramic approximately 1"x2''x3" with one bolt through the center and 2 wires just a few inches out to a connector. Power from the 12B577 relay box goes through this to the fan. The computer has to switch on the relay based on temp or a/c signal,

[RedFury]

Last time I had that same problem, it ended up being the temp sensor on the block. Certain cars, Like our dodge shadow, if you disconnect the wiring to the fan ( the connection to one of the sensors ) the fan would run all the time with the ignition on.

[bigblue77]

Well, looks like I am coming into this conversation to late. Sounds like its pretty much licked.

I have a 93 taurus that had the same problem once upon a time. Well, actually I don't think there is a problem that car hasn't had. Just last week I had to replace the heater core. Of course the boss saw that I could infact change those even tho I told him I had never done one before. To make a long story short, I have done two already this week. First was a 90 Grand Marquis, and the second on a 94 Grand Marquis. They are set up much like a taurus. I feel very sorry for anybody stuck with having to do one, I really do.


Sorry if I crapped on your thread.

Jer

[Brainchild]

I feel for ya bigblue, I've done 4 this year already, and fords are the worst, they really are.

DAve there is nothing I can add to what is already been suggested, let us know what happens. The temp switch is usually the cause of the thing not working IME.