Relay

[Joe Yakubik <75363.2524@CompuServe.COM>]

Jerry, 

According to my Bentley, the #2 relay is the second stage cooling fan relay.
Apparently the first stage (relay #3) is controlled by the A/C controller.  The
second stage (relay #2) is controlled by the A/C high pressure switch.  Both
these relays supply the fan through a set of (speed control?)  resistors.  These
resistors are on the drivers side of the engine compartment in a little plastic
housing.  They're is also a third stage relay (#7, aux panel).  The third stage
is controlled by the Rad cooling fan thermo switches.  It sounds as if it's
behaving normally, or as you would expect with a bad 2nd stage relay.

WARNING! WARNING! WARNING!

The Bentley here is WRONG!  The only problem is, I don't know how wrong.  In the
fuse box breakdown and the wiring diagram it says the first stage cooling fan
relay is routed through the "A" connector on the back side of the box and the
"K" connector is not used.  In my car, this is not true.  There is no "A"
connector and the "K" connector has wires that match the color and gauge for the
#3 relay.  

Coincidence?  I think not.  I think it's the other way around.  

The other thing to consider is the lack of fuse protection for the fan.  People
have described their cars as electrically self destructing due to a shorted fan,
or a seized-bearing-high-current-draw fire.  They have also praised the '91 as
having "good fuse protection".  The only problem is:  I don't see any good fuse
protection for the fan in the Bentley.  The components are protected, except the
fan itself.  But then, the Bentley's wrong here, isn't it?

There was a recommendation for installing a large fuse (a la the boom box radio
fuses) in the ground wire for the fan.  The fan has three power wires, so it's
kind of difficult to fuse the "plus" side.  If you are planning on taking a long
trip, you may want to do this.

Of course, you'll want to figure out why your relay fried in the first place.
I'd check the resistors in the engine bay.  A short (water, dirt, crud) across
the resistor would up the current (P=I^2*R) and maybe fry the relay.  It may
only have been a temporary short (car wash + A/C = poof, maybe).

Let me know what you find out.

Joe Yakubik

PS Ned said the 6 speed COULD be done (Researched it himself earlier, I can't
imagine why)  just not easily.  80/90 = S2.  200 does not equal S4/S6.