Wiring up the fan. Why the 2nd fan keep running.

I want to fix up the second fan myself but the header/extractor is blocking my clearance to mount up the fan. Since I was going to get Kenny to replace my oil pan. Might as well get him to fix up the fan.


This is a pic of a suzuki 1000 k3/4 fan as 2nd fan,
taken from hayabusa.org.
The bottom left is sharing the same point with the stock fan,
The bottom right needs a bracket coz its too short,
The top is sharing with the radiator mounting point.
In general, get the wire mesh facing down.

My purpose was to have the 2nd fan dependent on the stock fan to turn on. Which means when the stock fan turns on, it will trigger the relay for 2nd fan to turn on. Kenny seems to have a problem, he told me that the stock fan has a constant 12volt supplying and he did not understand why.
Following my method will keep the 2nd fan running all the time. After half a day of attempt, he gave up and add a switch point so I could turn it off whenever I wanted to.


Circuit diagram of the fan.
Kept going over and over but nothing seems wrong.

After 1 week of monitoring my house renovation. I've finally had the time today to reroute the fan's wire. I tried my method, 2nd fan's relay dependent on the first fan's current, 2nd fan current directly from battery. However, the 2nd fan still run immediately when the relay was connected to the first fan. I can't believe that my method was wrong but I finally gave up and ask some guys for advise.

In the end the answer was, The positive wire for the stock fan was a constant supply however why it did not run was because the grounding wire was not "close". No ground = no return path = OFF mode. Why the 2nd fan was turned on was because the return path was connected to a common ground, that grounding path was "close" all the time!!


After thinking the whole thing for a while, nothing would have gone wrong if I didn't add a relay. Without the relay, I would have tap the current and grounddirectly from the stock fan.


Messy wires for the fan.
I had a 10A fuse there directly from the battery to the 2nd fan.


Top of fan sharing mounting point with radiator.


Inner mounting point sharing with stock fan.


Outer mounting point need a bracket.


Before


And after.

Tested for overheat, when both fan first trigger, heat was brought down in 10 seconds when fans stops, 2nd time, 16 seconds.