Radiator fan questions


Okay, let's just say that a wise man once told "check the simple things first!" Maybe it was the wet weather, maybe I have to give in to reading glasses. Tore into finding the relays by removing the speedo, clock cluster. Found the relays, everything fine. Back to the fuse panel and sure as s---, blown fuse but in my defense the bloody wire is so thin you do need to look carefully. Fan work when pigtailed now we'll see on slow climbs.
Cheers, Steve


New member
Hi All,

I need to replace the radiator fan thermoswitch (the one screwed into the radiator, lower left) on my '85. Is there any problem in replacing it with the newer ('86-'91) switch that kicks the fan in at lower temps? The stock '85 switch is two stage, but the kick-in temps are higher and I can't think of any good reason for this.

I believe the stock thermostats for both 1.9L & 2.1L engines open at 87 degrees C so there shouldn't be any conflict there. Other than the fan motor wearing out a bit sooner from increased use, I can't think of a drawback to using the newer switch.

On a related note, if anyone has additional tips on how to replace the switch while minimizing coolant loss I'd love to hear them. Topping up and bleeding Vanagon coolant systems is not my idea of fun!

Thanks and happy motorin'



New member
No High Fan

I've got an '86 Westy 2.1L. Having an overheating light / hi fan problem. The overheating light comes on flashing in Stop and Go traffic, etc. The temp gauge is roughly between the light and the 3/4 temp mark.

My low fan comes on but the high fan doesn't. I did the fan switch test and both hi and lo fan worked fine. The fan switch test I downloaded said that if both fans came on that then the relay was OK. I checked the expansion chamber and it's full. The sensor looks OK. My only guess is that somehow the signal to run the hi fan is getting interrupted on the way to the fan switch, but I don't know where this might logically occur. I appreciate any suggestions or ideas.

p.s. The Vanagon has been great EXCEPT for this ongoing overheating business. Just when I think I've got it solved and relax (finally my bus is completely sound!), usually when I'm cruising down the freeway in a distant and unfamiliar place, it goes and overheats again. Doesn't matter if I replace fan switch, thermostat, coolant sensor, water pump, even radiator--sooner or later but inevitably it WILL start overheating again.
Just sayin'...

Capt. Mike

Gauge between ½ & ¾ is not overheating. Since you say you haven't tested the thermostats for the fan switch, do so. You can't rely on 'looks' to test an electrical component. "Downloaded" tests may be valid, but this site relies on the procedures in the Bentley (Guideline #2). Did you actually measure the temps at the appropriate points with a laser thermometer? This is the only way to determine if you are actually overheating. They can track temps from discharge from the head (hottest) all the way back to the water pump with just point & shoot. A discussion on this valuable tool is posted in the TOOLS forum. The light can also be activated by the low coolant sensor in the expansion tank. Since it works on an electrical current through a liquid, they can 'look' good but be coated or defective. Or the tank, which is supposed to be 100% full, may not be staying that full from make-up tank refill (pressure cap defect) and thus flashing low coolant rather than overheating. "Overheating . . ", "Coolant . . . hose & piping" and "Temp. warning light . . ." all have their own topics in this forum (Guideline #4).
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New member
I'm hoping to get help. I've looked at the Bentley wiring guide, but my brain is having trouble grasping wiring and wiring diagrams. sorry.

as I posted elsewhere, we had trouble on a trip and a shop suggested they put in a toggle switch to manually turn on the fan.

to my dismay, when I took off the grills today to work on the van, I saw that the wires had just been cut. and they cut all 3 of them close where they come out of the plug that plugs into the radiator. the wire going to the "temporary fix" toggle switch was hooked up to the wire for low speed. the high speed and power wire ends were just taped up. then two lighter gauge wires were cut and taped up. the three heavier wires, R/W, R/BK, R/BL are easy to see where to reconnect. but we are stumped over where to connect the lighter gauge wires, R and R/BL we remember they were connected to two of the heavier wires. (we think) but which two?

after replacing the thermostat and bleeding the coolant, the van was running without overheating. our next step was to see if the fan would come on when it should, but after seeing all those cut wires.....well, no wonder.

[Moderator Note: Insufficient information. What year & model? Read Guideline #3!]

oops. sorry. it is an 84 westy. with an 86 engine. I'm hoping to be able to call the shop that cut the wires this morning and ask them if they kept the connections. :confused:
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New member

fan is re-wired, and working. thermostat is replaced and opening, lines are bled. the temperature is staying where it should, fans are running when they should. I'm really not sure exactly what was wrong, all we replaced was the thermostat. somewhere in having a shop replace the heater valve that was broken, something started the problem.

everytime my husband and I fix something, we become more and more delighted with our van. And the more we fix the more we learn and the more "protective" we feel of just who works on it anymore. it's also pretty fun working under there together!

many many thanks for the e-mail help from this forum and to the shop in Tucson where we bought the westy, both who patiently answered our calls for direction answered with much patient advice and thoughtful prompting!


New member
low level fan relay?

hi overheaters,

i have a 1988 Vanagon GL that has just started to do the overheat dance.
it happened on a long trip towing a trailer.
the temp climbs and climbs then the light comes on, and then it passes the little white line of potential head and engine death.
anyways, after checking hoses and cooling system for cracks and worn parts, replacing caps, replacing some smaller hoses on the self bleeding system, flushing, bleeding, ensuring fuses are intact and conducting, making sure my heads aren't blowing air, (deep breath in) AND making sure the radiator actually works and has flow, i decided to do the jump wire test on the thermocouple sender.
and i should have done this first.
it seems that i only have a high speed fan option. the low level fan doesn't come on at all.
i understand that i need a relay called a "low level fan resistor" and it's located behind the DS headlight. and that's awesome. so much less headache than i anticipated.
but i can't find one.

i'm worried i will ruin something if i don't replace this thing.

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New member
Rad fan for 85

I am having problems finding a new rad fan for my 85 with A/C, The numbers on the motor are 251 959 455.... 12V S985....AEG L76A60 87863. The problem is a worn self aligning bushing. The questions is, can I use a later model rad fan which I can get no problem. I know I need a different shroud as the mounting is different, but would the wiring control and capacity accept the 86 to 91 motor.


New member
i have an 83 westy with no ac and im thinking the low speed of the fan is not kicking in. my westy is not overheating but my gauge rises over the halfway point and i still do not hear the fan kick in. i jumpered the plug that connects to the temp sensor and i can get the high speed to kick on but no low speed any advice?


New member
Not to sound harsh, but if your not 'overheating' then why is it an issue? The hotter you run without damage, the more efficient the engine (generally) so if you are not 'overheating' then you are in a good place.

We also need to be careful about the use of the term 'overheating'. Without specific temperatures at specific places, we have no idea if you are 'overheating'. Gauges are mechanical and subject to wear, temperature sensors are mechanical and subject to change and all of these components have a manufacturing tolerance when new which means no two are truly the same. When you add up the possible tolerances of each component then you can see the variability of one vehicle to another.

For your year, the book says the stage 1 fan comes on at 93C-98C and goes off at 88C-93C. The stage 2 fan comes on at 99C and goes off at 91C. As you can see, large temperature spread and cross over from one to another. This just aggravates the possibility that you are concerned about normal operation of your vehicle.

My advice would be to drive under different climatic conditions (ambient temps, humidity etc.) and get a 'feel' for your individual vehicle. After you have driven it a while you will get used to what 'normal' for your vehicle is. If that changes, then it is time to look for a mechanical issue that is changing the behavior of the vehicle. Just note that the warmer it is outside will influence the temperature of the engine and the point where the needle sits. Idling versus driving / long uphill pulls versus downhill 'coasting' all may also affect the needle position depending on how closely you monitor it. AC will also have an affect but you don't have that so you won't notice a difference.

If you are so concerned then a manual switch to control the fan might be your answer.

Happy motoring.