5KCS Fan Low/Medium Speed

[james accordino]

My mid-speed relay was almost totally burned.  Plastic
cover melted etc.  I'm NOT exactly sure what caused
it.  I think it might have been a combination of
slightly dirty contacts and a fan motor going south. 
The fan motor definitly had increased resistance,
especially on initial start.  I replaced both the
relay and the fan with a 7 blade job I got off a
wrecked '90 200 with 22k miles.  This has solved the
problem, although I still don't know what the exact
cause was.  Sometimes it's a cumulative failure. 
Lot's of little problems conspire to take out a
certain system.

Jim Accordino
--- Steve Sherman <spsherm at attglobal.net> wrote:
> I think I have lost my low & medium speeds on my
> radiator fan.  Just
> noticed the engine temps climbing higher than usual
> and the lack of any
> fan noise.   Fan is still working in that it will
> come on after the
> ignition is off or if I short out the afterrun
> terminals.  But when
> running, no fan until temp reaches about 65% of the
> temp gauge (much
> higher than before).
> 
> I've checked and no blown fuses.  Also thought that
> it might be some
> relays for this, but the diagram on the aux relay
> panel is useless for
> identifying what's what.
> 
> Can anyone give me a part # and definite location of
> the relays that
> control the low/medium fan speeds.  Also, any other
> things to check
> before running out and getting new relay(s) (e.g.
> can one bypass the
> radiator temp sensor on this to check the
> relay/circuit?).
> 
> TIA
>