I have a 2005 Suzuki Vinson 500 L.E. 4x4 automatic. I bought it used a while back, haven't had any issues out of it until now. Last Wednesday the wife and I went riding for a few hours in some local trails....nothing major just really cruising around enjoying the scenery. When we got back we tag teamed the cleanup before putting the machine in the garage. We washed with dish liquid and water......I then let it dry for about 30 mins or so before pulling it into the garage. Anyway, when I shut it off to wash it....no probs, no lights....everything normal. After the wash, the second I started it the (RED)temp light comes on and stays on. I figured it wasn't anything important because it came on at start up so I just let it go. Since then, nobody has ridden it. Today I decided to go for a ride and once again, the very second I started it....there it was staring me in the face again. So I shut it off....checked the coolant level.....everything was good. I then checked the radiator to see if it had any debris on it, and it also looked great, I left the cap off the radiator and started it to see if the coolant was cycling through the radiator and it is just fine, the fan kicks on as normal and shuts off like normal. So I put everything back together and took it down the road. Here in KY this morning it was about 45 degrees outside and I got about a mile down the road and the light started to flicker and eventually went off. Then I stopped to turn around and within a couple seconds....it came back on. On the way back.....it went back off after a small flicker and came back on when I stopped again. No abnormal noises, no loss of power, no steam or smoke....nothing abnormal at all, just the light. Now after I got back and seen there was nothing I could tell, I loaded it up, took it to my buddy's house and we went riding for about 4hrs. No problems AT ALL! Anytime we were on the road going from trail to trail, it would go off, but the entire time we was in the woods it stayed on. After getting back without any issues, the light remained on. We let them cool off and sprayed them off. When I turned it back on to load it into the truck, it was off......5 mins later, back on.

Here is the kicker tho......when it comes on, you can be sitting still and just tap the throttle and it will flicker just a bit and go off......then come back on, hit the throttle again.....flicker off.....Almost like a loose or wet connection. I don't know. I took the bottom radiator hose off, drained the radiator, flushed it about 5 times, and still doing the same thing. I have no idea what this could be because it doesn't affect how it runs at all and if it wasn't for the light you wouldn't think anything was at all wrong. The light comes on when you just turn the key to the on position even if you don't start it, and stays on.

Below is a video I took today of the light and messing with the throttle. Hopefully it helps someone help me. Thanks a bunch in advance!!!!

 

It’s a while since I worked on a Vinson but I recon it will be similar to other Suzukis in having two temperature sender units, one for the fan and the other for the light. If the warning lamp is coming on with the engine cold, it is probably either a faulty sender unit for the light or a short on the wire from the sender unit to the bulb. If it has a two wire sender unit like most Suzukis a short would blow a fuse, so try a new sender unit, if it has a single wire sender like Hondas, a short just lights the bulb.

 

Thank you very much for your reply. I went to 3 shops today and explained the issue and showed them the video. They all seem to be on the same page as you....a faulty temp sensor. I came home unhooked the sensor and the light went off, I then removed the sensor from the head and cleaned it. After re-installing the sensor I plugged it back in and still the light. I ordered a new sensor, unfortunately it wont be here till next week. BTW....it has 2 wires coming off the sensor and connects with a barrel style connector.

I'll post if the sensor is the fix. Thanks again!