Thermo Fan Switch

Just looking for an updated recommendation re replacement thermo fan switch for my 1985 VF1000FF.


Hey bulldog, i dont know specifics but the easiest way is to go into your local red devil or natrad radiator shop. They maybe able to match size and thread, resistance value with a small car one. Like the suzuki mighty boy or subaru fiori. Me personally i would go to the local wrecker yard and pull every small car one to find as close a match as possible. For example i have a honda vt500e 1983. The thermostat from the fiori fits and works. So you never know. Half the fun is finding.

Hi bulldog, I have the this lower temp fan switches on all my vfs, comes in about 10/15° lower.
rover part BNP1883
There was loads of them on ebay and also some cross reference part numbers, think they were about £15.

Thanks for the info.

Thanks will have a look

Hi, Pete,

Does the original connector fit to the BNP1883 switch without modification?

I’ve just experienced the “in the red, no fans on” phenomenon; it had a new switch fitted when it was being restored, so it’s a bit annoying :confounded:

I would say: “no” …


The original switch has the connecting to GND inside.So you have to mount a new connector to the cable and connect the other pin with a new cable to ground.

I just searched a little bit in ebay.

Universal Temperaturschalter, Öffner / Schließer / M16x1.5 | eBay

this should be plug and play and you can select the switching point. (If thread M16*1.5 mm is correct)

Doesn’t the fan switch just switch the live supply to the motors, with the earth return being via the motors themselves?

There are two connectors on the switch that’s fitted.

As far as I can tell, the only devices of this nature with a single connector are the oil pressure switch and the thermistor for the temperature gauge.

Maybe F and R are different, but I assume not …

SWITCH ASSY.,THER for VF1000R 1986 (G) - order at CMSNL

Honda VF1000R SC16 1984-1986 Kühler, Wasserkühler | eBay

On both there is only one connection for the fan switch. The housing is the connection to ground (via screw from radiator to frame).


you are right …

SWITCH ASSY.,THER for VF1000F2 1985 (F) - order at CMSNL

they don’t have the radiator connected to GND. But Honda uses 6.3 mm flat connectors, not the round 4mm ones.

I fitted a lower temperature switch that had 2 flying leads on it and put crimped lugs on to match original connector. Most people if they’ve had previous problems fit an override switch as the radiator only has to lose a small amount of water before the sensor no longer works so you have double the problem, low coolant and no fans. I fitted a nice little illuminated switch on the handle bars next to throttle but as the fan switch only switches the neutral I had to install a relay so the illumination worked.