Radiator fans not working? Removed your AC?

[Lawrence Weeks]

Once upon a time (Wed Aug 21), Mike Jez wrote:

> -- Yep it just hangs there, I removed everything from the AC system
> but the evaportator- dont feel like it just yet. I didn't do anything
> special to the wireing of the AC system after removing the AC 2 years
> ago when donig the DET swap. I just put a alternator in my SE-R after
> 12 years of use, and I know all the wires just hang there. I get the
> AC light to come on when I hit the button on the dash, idles higher,
> and fans kick on high speed.- they got 2 speeds low and high. I do
> not have a FSM here right now to tell ya exacly how my 93 is.

Once upon a time (Thu Aug 22), Lee Koloszyc wrote:
> IF you pull the fuse for the AC, the AC fan will come on.

Once upon a time (Thu Aug 22), Stewart, Joe (COX-Atlanta) wrote:

> Pull the temp switch and see if both fans come on high. This will
> tell you if there is a wiring fault somewhere. (No temp sensor
> signal = both fans on high.)

To beat a dead horse... I have been studying the wiring
diagrams. First, a '91-'92 SR powered car with a manual transmission
has single speed fans. Second, the fans are powered together by a
single relay controlled by a single line out of the ECU, so it is
not possible for just one to run. I don't know about post '92 cars,
never had one. :-)

As for my issue, I have no clue what was causing it. All I know is
that with the dual pressure switch disconnected, my fans never came
on and the coolant gauge would just keep going up. After hardwiring
the DPS wires together, the fans now come on when they should, and
the engine doesn't overheat. The only thing the DPS does is act as a
gateway for the signal to the ECU as to whether or not the AC should
be turned on. Open DPS circuit = no AC activation. So it shouldn't
make any difference as regards engine temperature. The fact that it
did make a difference means I have something else to track down. Maybe
this is just some bizarre coincidence.

BTW, if the DPS is disconnected, then the AC switch will not cause the
fans to turn on, at least in a '91-'92 car. With that disconnected,
the ECU cannot know the switch is on, and will not turn on the
fans. From what Mike says, it looks like a '93+ is different.

BTW 2, in the wiring diagrams, what is the difference between a junction
with an open circle vs. a closed circle?

Larry
--
Lawrence Weeks      "Audaces fortuna juvat."      dev@anabasis.net