Date: Fri, 18 Feb 2000 14:18:46 -0500
Reply-To: John <johnpatt@WARWICK.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John <johnpatt@WARWICK.NET>
Organization: PattonSystems International
Subject: Re: Radiator Fan Switch
Content-Type: text/plain; charset=us-ascii
Vince Nash wrote:
>
> Hello, I'm Vince and I'm fairly new to the list. Maybe someone came help
> me. Yesterday I took a 3 hr. trip to Raleigh to pick up a fifth chair, on
> the way back I noticed the temp gauge was at about 3/4. About 5 seconds
> later the red light came on and the gauge immediately maxed out. I quickly
> pulled over to the shoulder of the road and turned the engine off. I
> checked the engine compartment and the overflow or refill tank was full and
> was peeing coolant out the little holes in the top of the tank. I did
> notice that the radiator fan never turned on. I waited about 45 min. to
> let the engine cool down. I filled the refill tank back to the max line
> with water that I always carry for the unexpected. On the way back the
> gauge started creeping up above half way. So I turn the heater lever to max
> and within a few minutes the temp gauge was back to normal (about half way).
> I talked to my local foreign car repairman. He said to remove the lower
> front grill and unplug the fan and you'll find a 3 prong connector, and to
> jump one point to another to see if the fan comes on. I did this and the
> fan came on, there are 2 speeds. He said if the fan comes on by doing this
> but won't come on automatically when the coolant gets too hot that I need a
> Radiator Fan Switch. Does this sound right? Or is there something else I
> need to check? Any input to this would be greatly appreciated.
>
> Vince in NC
> 85 Westy
> 99 Beetle
Hi Vince,
Regarding the the radiator fans switch, I've read the advice you
received but I disagree. I have two coolant sensors on my 2.1L Syncro.
One is the actual engine temp and the other is the temp of the coolant
returning from the radiator. First when cruising the radiator fan should
NEVER cycle on. At cruise depending on ambient temp, I see 40*F to 115*F
returning from the radiator-even at 70 MPH. This is well below the fan
switch thresholds of ~195*F & ~215*F. The fan should only run at
standing idle or slow speed and when the A/C is on. Even at idle my
cooling fan doesn't cycle on until the returning coolant temp hits at
least 160-170*F. If you need the cooling fan running at highway speeds,
I don't think the fan switch is the answer.
Regards, John
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