On an 87 with AC the more likely culprit is the speed resister located behind the left side headlight assembly. On this set up both speeds use a relay. Low speed is on the fuse box. High speed is above the fuse box under the dash. It gets a fusible link and a separate supply wire from the battery.  The AC system should operate the fan also on a low speed anytime the compressor is running. If it does not along with the radiator not turning it on the resistor is the common problem. Also there is a 30 amp fuse for fan controls and low speed. 

 

Dennis

 

From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of David Bjorkman
Sent: Tuesday, September 18, 2012 3:30 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Radiator thermo switch

 

Hi Volks;

All of a sudden, my radiator fan only works on high.  I was driving slowly in traffic, with the A/C on .  My lovely wife looks over and says "Gee, I've never seen the temp guage that high".  Holy smokes, I look down and the needle is at least a full needle width above the LED (Inline 4 FAS motor-cast iron -:)).  Even in Mesa, AZ this past June at 110+ F with the A/C on I have never seen it that high.  I wasn't even sure the gage itself would go that high.  Well, just at that point the high fan kicked in.  As I thought about it, I had only heard the fan kick in (I usually kinda note those things as past esperience is a harsh teacher) on high at all that afternoon.  I have heard that A/C has some sort of a high fan kickin, althouht I am not sure how to tell the thermo switch high fan from the A/C high fan, if there is one, so I am not sure if the thermo switch was working at all, but the fan sure was.  I took the bus onto a street where I could travel at 30-40 MPH and it cooled right down to just below mid LED, where it usually runs.  

Anyway, unless someone thinks otherwise and can enlighten me, I am assuming it is the radiator thermo switch.  Haven't looked yet, but can I trust a FLAPS switch (if avaliable, to save me a wait for the mail), or should I go right to one of our friendlu, helpful vendors?

 

Dave B.

'87 Westy w/FASTT inline 4

'84 Westy WBX