84 4ksq Radiator Fan Question...How High?

[L DC]

To add to Huw's input.

Have flushed and/or refilled the coolant/H2O?

If there is air trapped in the cooling system, liquid
won't circulate properly and, thus, fan switch,
located at the bottom of the radiator as Huw
indicated, won't kick in.

If there is air in the system, purge it. I forget if
your system (usually on the radiator) has a purging
valve. Anyway, the way I purge it in my car is by
leaving the reservoir cap off and let the engine run
at idle until warm and liquid starts to bearly
overflow over the neck of the reservoir cap. If liquid
level falls down as air gets out, fill with liquid
during thr process.

Put reservoir cap on and turn engine off. Start engine
again and let it run at idle some more, while watching
temp gauge as well as to see if fan kicks in.

Let the car cool off and then take reservoir cap off
again, which should be pressurized and liquid level
perharps lower.

Top off with coolant/H2O and repeat process as needed
until fan comes on on its own, provided the fan,
relay, harness in working order.

The fan itself could be failing.

Both of the above has happened in my car. I now have a
manual switch, relayed, running to the fan on the high
speed setting just in case the fan switch fails; I've
been there also.

-Reagards,

Louis




--- Huw Powell <audi at humanspeakers.com> wrote:

> 
> > I’m beginning to suspect that the radiator fan in
> my 84 4ksq is not going to
> > “kick-on” soon enough to avoid blowing the (upper)
> radiator hose.  All
> > connections to all fittings appear to be solid
and
> I even a have a few
> > relatively recent electrical components in the
> cooling system.  I’m losing
> > my nerve relative to sitting in the car watching
> the temperature gauge and
> > keeping my fingers crossed that the hose doesn’t
> blow.  I let the gauge go
> > at least ¾ of the way up.  Should I just stop
> whimping-out and let it
> > go?...or is there a quick way to by-pass the rest
> of the cooling circuit to
> > check the function of the radiator fan? 
> 
> The sender for the fan is in the bottom rear of the
> radiator.  Shorting 
> its connector out should make the fan run.
> 
> The sender does this by turning on relay #2 which
> sends battery power to 
> the fan.  That relay should also be tested or
> replaced, and can be 
> jumped to, again, run the fan.
> 
> You can also run heavy jumpers to the fan motor
> directly from the 
> battery to see if it runs.
> 
> While running the engine up to that 3/4 position on
> the gauge, you can 
> measure the sender's resistance, it should go from
> infinite to zero at 
> some point.
> 
> You could remove it and test in a pan of water as
> you boil it, but then 
> your coolant would pour out of the radiator.  Unless
> you have a spare 
> sender to screw in its place quickly.
> 
> -- 
> Huw Powell
> 
> http://www.humanspeakers.com/audi
> 
> http://www.humanthoughts.org/
> _______________________________________________
> quattro mailing list
> quattro at audifans.com
> http://www.audifans.com/mailman/listinfo/quattro
> ---
> Watch this space for ads :)
> 



 
____________________________________________________________________________________
Have a burning question?  
Go to www.Answers.yahoo.com and get answers from real people who know.