How-to, very simply, trouble shoot the Radiator Fan system on 83.5-91 watercooled (non-diesel) Vanagons.
- Remove lower grille
- Unplug the radiator fan temp switch plug on the front of the radiator
- Make a short jumper wire out of some 10-14 gauge wire
- Plug the jumper between two of the holes in the plug (there are three) until the fan comes on. (I forget which holes but you can figure this out easy).
- When the fan comes on, try swapping one end of the wire out into the other hole until you get the second speed working.
- You should be able to have two speeds (low and high and you will be able to tell the difference as high is like huricane force).
- If the two speeds are working then everything in the wiring is good (fan, relays, wires, plugs etc).
- If only the high speed is working then your radiator fan resistor is bad and needs to be replaced. We have these in stock just give us a call.
- Now run your van up to temperature.
- Not far past the center on your coolant temp gauge (to the left of the LED) the fan should come on low.
- If the fan comes on, then you should be OK. I don’t think you can get the van hot enough to check the higher speed just with the van idling.
- If the fan doesn’t come on at all or only the high speed comes on at a higher temperature then your radiator fan sending unit is bad and must be replaced.
This is just a simple trouble shooting plan for this system but it works well and will tell you in a very short time exactly what your problem is and how to fix it.
Hope this helps,