Re: Cooling Fan Fuse - Was Why does the (steering) wheel wobble?

[Eric Maxon <emaxon@megsinet.net>]

Mark Pollan wrote:

> Eric wrote:
> >Put an appropriate amperage inline fuse in the radiator fan's power
> >wire, right at the fan-- the fuse is often on the coil side of the
> fan
> >relay, and will not protect the circuit if the fan blows shorted.
>
> This definitely caught my eye!  What is an appropriate amperage?  I'm
> specifically interested for an '86 5KCSTQ but I am sure others would
> be interested for their specifics.  So, what say ye?
>
> TIA,
>
> Mark Pollan

For the 500W fan in the 5KCSTQ (Used in the 200 also???):
I=P/V=500W/12V=41.6A  which is the current draw of the fan, assuming all
is well.  The original relay for this circuit has a 70A capacity, the
supercede relay has a capacity of 60A... I'd put in a 60A fuse.. this
shouldn't blow unless you have a bonafide problem, and will definately
blow if you have serious wiring trouble or a short in the windings of
the fan motor... which is what you WANT to happen.

C'mon guys... Ohm's law.. this is basic stuff.

For the 350W fan used in non-turbo 5000's, 100's:
I=P/V=350W/12V=29.2A... so I'd go with a 40A fuse. (The rating of the
relay?)

I've been using a 30A fuse for 4 cylinder 4000's.

In general, look at the current rating of the fastest fan stage relay...
use a fuse of the same rating and sleep tight.

Eric Maxon