

1996 Kawasaki ZL600 Eliminator - Radiator fan will NOT come on
(The pictured radiator and fan above is not actually mine, just posted for visual reference)
I’ve been struggling a bit with this for the past week. Radiator fan suddenly stopped coming on and is causing cooling issues and boiling coolant.
The thermoswitch in the radiator on this model has a single terminal which acts as a ground when it triggers. I shorted the wire that connects to this terminal to ground, to bypass the switch and test the fan, and the fan ran without issue.
After confirming the fan was operational, I replaced the thermoswitch with an Amazon unit that was like $12. Did not fix. After that, I replaced it with an OEM sensor. Still has not fixed.
I cleaned the terminal connector and bolt on what seems to be the fans ground cable (the center bottom bolt in the radiator assembly picture above).
Planning to try to clean the threads themselves where the fan switch threads in as well as where that bolt threads in (though I’ll probably double check continuity or maybe even try grinding that fan wire to a different spot on the radiator.
I’ve boiled over the coolant a few times thinking I was good, but temp light on my cluster never came on, so really hoping I haven’t caused any serious damage.
I did try a manual fan toggle switch for a day which worked, but I put it in a horrible spot and I forgot to turn it on AND off in the same day so I pulled it off, and I’m just gonna fix it properly.
Hoping for any direction or insight into this. It’s been pretty frustrating.
I’m like 99% certain the radiator is properly grounded, as I checked for continuity on multiple random bolts, the exhaust manifold, etc
Edit: Resolved!! I determined it was a pressure issue (hoses were soft), and double checked the new radiator cap. The ridges that the cap uses to press down on the top of the filler neck are worn, so when fully tightened, it actually loosens. I tightened the cap just short of full stop and now it’s sealing and maintaining pressure. Fan also came on properly with the fan switch. It’s resolved!!