Date: Wed, 25 Aug 1999 14:26:26 -0400
Reply-To: David Beierl <dbeierl@IBM.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: David Beierl <dbeierl@IBM.NET>
Subject: Re: 2 Speed Cooling Fan?
In-Reply-To: <84cd79cf.24f57956@aol.com>
Content-Type: text/plain; charset="us-ascii"; format=flowed
At 12:52 8/25/99 -0400, Brian Doss wrote:
>I'm not positive, but I think that an '88 should have a two-speed fan. Is it
>the ceramic resistor that actually controls the kick-in of the fan?
The fans themselves are two-speed -- the A/C setup adds a resistor or two
into the mix so you get either three or four speeds, I forget which.
> Lately, I
>think that my fan only kicks on just before the point at which the engine's
>ready to overheat. When it does, it sounds like a C-130 takin' off!
That would be the high speed... :)
> So, I
>believe that the low-speed setting is being passed up. Sound right?
Yup.
> Anyone
>know how to test?
Unplug the connector at the rad thermoswitch and jumper from power to each
of the other two wires separately. If it's not obvious which is power, do
all combinations, no harm. If you use a paperclip don't hold it in your
hand, you might get a surprise (might get hot). You should end up with two
distinct fan speeds, not including off. If you do, the presumption is you
have a bad thermoswitch (or bad contact on the low-speed lead coming from
the switch). If you don't, there's an open in the low-speed wire somewhere
btw there and the fan, or possibly a bad fan.
david
> I checked the archives, but did not come up with the
>two-speed hypothesis, just how to see if the fan works. Also, I changed my
>thermostat a few months ago, and I have noticed the temperature needle riding
>higher than before, but, I'm not sure exactly how these two things really
>affect each other.
If you had an 80-degree thermostat and put in a stock 87-degree one you
would see usually the needle riding around the upper edge of the LED, where
before it might have been around the lower edge.
>In other words, I don't see the harm of the engine running
>at a slightly higher temperature, as a matter of fact, I bet it's a little
>more efficient that way.
Some people believe that using a lower-temp thermostat is desirable for
lowered pressure-stress on the cooling system, or possibly against
localized overheating inside the engine. I think that the first is
unnecessary and have no opinion about the second -- not even sure that it's
been advanced as a reason. YMMV.
david
David Beierl - Providence, RI
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"
